The final hour of the 61st 12 Hours of Sebring offered a few big surprises in two classes that appeared to have been settles prior to the 60-minute run to the finish.

The fight between the two Audis heated up, and with traffic delaying Benoit Treluyer in the leading No. 1 R18 e-tron quattro, Tom Kristensen swept ahead in the No.2 for a brief moment before the lapped car allowed Treluyer back in front. The duo made light contact but both continued unimpeded at the head of the field. The two would cross the finish line in that order with Treluyer holding a 17.5-second lead over the Le Mans legend.

In P2, Marino Franchitti led home Level 5 teammate Ryan Hunter-Reay by nearly two minutes as the Scot dialed back his pace with a comfortable margin in hand.

Risi Ferrari's amazing return to the ALMS looked like it was destined to be completed with a victory in GT, but Sebring rookie Matteo Malucelli, who took over from team leader Gimmi Bruni when the Italian began experiencing back pain and numbness in his legs, ran long into Turn 10 with the No. 4 Corvette of Tommy Milner in striking distance with minutes left to go.

Milner made the pass for the lead as Malucelli steered his Ferrari back onto the tarmac, but the damage was done. After two bouts of serious electrical problems seemingly ruined the No. 4's day early in the event, the defending ALMS GT champions secured an amazing win thanks to virtuoso performances by the Corvette Racing crew and drivers.

Jeroen Bleekemolen's No.22 GTC Porsche was stalking Damien Faulkner for the lead in the final half-hour of the race when Faulkner's brakes began to fail. After fighting back from a pit lane issue just an hour before Faulkner lost the lead to Bleekemolen with 34 minutes left to race.

In PC, former Indy Lights driver David Ostella caught and passed Kyle Marcelli to claim the win for PR1/Mathiasen.

Heartbreak followed Damien Faulkner from the Rolex 24 down Highway 27 to Sebring as the Irishman lost the lead in the closing stages once again as the brakes on his TRG Porsche surrendered prematurely.

Early GTC race leader Jeroen Bleekemolen in the No.22 Porsche capitalized on his rival's issues to take a comfortable win over Spencer Pumpelly. Faulkner, who faded without stopping power, was third on the final lap and nursing his brakeless Porsche but stopped short of the line to take a cruel fifth-place finish. 

 ***

SRT Viper's dream run on its Sebring debut took a major blow just five minutes into the 10th hour of the race.

Shortly after taking second from the No. 17 Falken Tire Porsche, Ryan Dalziel's No. 91 Viper stalled on pit lane and refused to fire. The car was taken behind the wall and with the issue traced to the electronics, the Bill Riley-led team got the car running again, albeit with Dominik Farnbacher behind the wheel. The repairs would cause the viper to lose three laps. The No.17 Porsche suffered dramas as well as Bryan Sellers was forced to pull off with cramps and hand over to Nick Tandy.

The leading pair of Audis pitted a lap apart, and as Olly Jarvis departed pit lane in the No. 1 R18 e-tron quattro, Allan McNish came storming past into the lead in the No. 2. The No. 10 Dempsey Racing GTC machine pitted with a flat tire just 20 minutes from the end of the 10th hour as the No. 8 of Stefan Johansson spun out of second in PC right in front of McNish. Despite that spin, Johansson maintained second and took the lead as Mike Guasch in the No. 52 PC car pitted for tires and fuel.

Level 5's Ryan Briscoe led P2 from teammate Simon Pagenaud in the other L5 HPD while David Ostella remained in control of PC from the No. 8 of Kyle Marcelli. In GT it was Olivier Beretta in the No. 62 Risi Ferrari by over a minute from the No. 4 Corvette of Olly Gavin. Damien Faulkner in the No. 60 GTC Porsche led at the end of Hour 10 from Jeroen Bleekermolen by 47 seconds.

***

At the start of Hour 8, Muscle Milk Pickett Racing P1 pilot Klaus Graf started the eighth hour the same way he ended the seventh – in the penalty box. This time the No. 6 made side-to-side contact with the familiar target of ESM P2 driver Ed Brown. That drew a second penalty in the space of an hour and Graf was furious.

“This is not fair,” said the frustrated German.

The No. 8 PC car of Kyle Marcelli pitted from the lead halfway through hour eight and had the nose replaced. GT leader Richard Westbrook made contact with Bill Sweedler 45 minutes into the hour, and was promptly served with his own stop-and-hold-for-60. A few laps later something failed on Sweedler's Ferrari and he made heavy impact with the wall, triggering the fourth full-course caution.

Under yellow the Audi squad repaired the damaged undertray on the No. 1 car and sent Marcel Fassler out on time to retain the race lead. Most of the field took the stop under yellow with the Audis holding station at the front of P1 ahead of Nick Heidfeld in the No. 12 Rebellion-Toyota.

Level 5 held its firm grip on P2 as Marino Franchitti led P2 in the No. 551 HPD ahead of teammate/team owner Scott Tucker while Mike Guasch led PC in the No. 52.

Craig Stanton in the No. 62 led GTC while Oliver Gavin closed the hour in the GT lead. That will change at the turn of the hour though as the No.4 Corvette will take a 60-second stop penalty for co-driver Richard Westbrook's role in the Sweedler contact.

“That's just ridiculous,” Westbrook said after handing off to Gavin. “[Race Director Paul Walter's] got to have a chat with himself up in race control because he's killing the racing.”

***

Hour 6 was packed with GT action that also saw traffic between the five classes lead to plenty of paint swapping.

The P1-leading Audis pushed continuously as the Nos. 1 and 2 traded the overall lead on multiple occasions.

The No. 01 ESM P2 entry of David Brabham suffered an input shaft failure while the Aussie was at the wheel, stranding him on track and triggering the day's third full-course caution.

Under the caution, the No. 1 Audi took a long stop to inspect bodywork damage leaving Kristensen in the lead in the No. 2 R18 e-tron quattro. Nicolas Prost held third aboard the No. 12 Rebellion Lola-Toyota.

P2 was a Level 5 affair as Marino Franchitti's No. 551 HPD led the sister No. 552 of team owner Scott Tucker.

The No. 8 continued to lead PC with Kyle Marcelli at the wheel while David Ostella held second place in the No. 52.

Late in the hour, Olivier Beretta lead GT in his No. 62 Risi Ferrari, and for the first time in the race, the No. 22 Porsche was not leading GTC; Dion von Moltke 20 was seconds behind class-leader Jon Fogarty in the No. 11 as the race reached the halfway point.

***

Hour 4 opened with a set of pit stops for the leaders in all classes, with Marcel Fassler handing over the race-leading No. 1 Audi R18 e-tron quattro to Olly Jarvis which promoted Allan McNish back to the point in the No. 2 Audi.

Fans of the Dodge brand and the SRT Viper line will remember the fourth hour of the 2013 12 Hours of Sebring as the period where the marque returned to the front of the GT class as Dominik Farnbacher worked incessantly until he had the chance to pass BMW's Joey Hand with the No. 91 entry.

McNish pitted from the lead and handing off to Lucas di Grassi. The Scotsman said he was surprised by the penalty levied after contact with Mirco Schultis but had confidence in the speed of the car. “The car's good,” he smiled. “It's an Audi.”

The Dyson Racing Lola-Mazda once again suffered ignition problems in the fourth hour, this time blocking pit entry briefly before Guy Smith's mount was pushed out of harm's way.

Former Team Penske IndyCar driver Ryan Briscoe had an electrical issue with his digital dash which necessitated an unscheduled stop in the No. 551 Level 5 HPD P2 car, and was able to return after a replacement was quickly installed.

With just 10 minutes left in the hour, ESM's Ed Brown had another spin, looping the No. 02 P2 car in a mid-speed corner. With his car beached on a curb, a full-course caution followed to rectify the situation.

At the end of Hour 4, di Grassi led in the No. 2 Audi led under yellow from Jarvis with the No.12 Lola of Neel Jani three laps down in third.

P2 was a far closer affair with Simon Pagenaud's No.552 APD just 20 seconds back from Guy Cosmo in the No. 01 ESM HPD.

David Cheng's No. 52 led Alexander Popow's No. 9 in the Prototype Challenge class.

Farnbacher's No. 91 Viper and Hand's No. 56 BMW remained locked together at the head of the GT field as the field filtered through the pits under yellow at the close of the hour.

Cooper MacNeil swapped with Jeroen Bleekemolen mid-way through the hour in the GTC-leading Porsche 911 GT3 Cup car.

***

Hour 3 of the 12 Hours of Sebring started out with a bang as Ed Brown, Patron CEO and co-driver of the No. 02 ESM HPD P2 car, turned down on the No. 552 Level 5 P2 car piloted by Simon Pagenaud at the scary-fast Turn 1, causing both cars to spin after the Frenchman had taken the corner.

Brown's careless move would go unpunished by the series, although damage suffered to his car required repairs which cost the team seven laps.

Audi kept the No.1 car of Marcel Fassler out on track during the caution, preventing their rivals from getting back to the lead lap. That left Fassler to lead from Allan McNish briefly until he was forced to pit for fuel.

The 3-way battle for the lead in the GT class was enlivened by lap traffic midway through the third hour, with Bryce Miller's Porsche refusing to give his lap easily. That created havoc for the No. 56 BMW of Joey Hand and the No. 62 Ferrari of Matteo Malucelli as they fought to catch the No. 4 Corvette of Richard Westbrook.

McNish collided with the No. 81 P2 car of Mirco Schultis who was meandering through the left-hand Turn 11 section. Schultis veered to the far right—well off the apex—forcing McNish to nearly take to the grass as he went around the outside. Schultis, unaware of his placement on the track, clipped the passing Audi, causing himself to spin. Schultis's hasty rejoin was a near-disaster with Malucelli in the Ferrari missing the ORECA by inches.

McNish pitted soon after for a scheduled stop and rejoined still in the lead – but not for long. The fiery 2-time Le Mans winner was given a 60-second stop penalty for his part in the contact with Schultis and dropped back to second.

The No. 16 Dyson Racing Lola-Mazda has endured a frustrating season opener, with team principal Chris Dyson encountering electrical issues that would send the P1 car behind the wall for more than 30 minutes. Meanwhile ESM P2 driver Ed Brown had two more spins in short order to make it three for the hour.

Richard Westbrook pitted from the lead late in the first hour with a jammed dash board, gifting the lead of GT to Joey Hand. With no dashboard functions and no pit-lane limiter, Westbrook's problems were compounded when he was handed a penalty for speeding in pit lane.

The third hour ended with Fassler leading from McNish in P1 despite a bobble into turn seven and Scott Sharp's No. 01 HPD leading P2 from the Zytek of Eric Lux with Simon Pagenaud in third.

David Ostella led PC aboard his No. 52 Oreca with Bruno Junqueira 25 seconds behind in the No. 9 while Hand led GT from Malucelli.

Cooper MacNeil maintained control of GTC in the No.22 over Alexandre Imperatori in the No. 44 Porsche.

***

Hour 2 at Sebring saw Audi's Allan McNish chase down and pass teammate Marcel Fassler under braking into Turn 7, but the Scot's lead was short-lived as a caution period for the stricken DeltaWing was used to pit for fuel, handing the lead back to the No. 1 R18 e-tron quattro.

DeltaWing's Andy Meyrick brought the car back to the 3.7-mile circuit after repairs were made to its engine, but the brand-new power plant soon went terminal, billowing smoke and flame from its single exhaust. The No. 0 P1 car completed 10 laps under the auspices of the Don Panoz-owned, Dave Price-run outfit.

Early in the hour Allan McNish took over the No.2 Audi and immediately scythed his way past traffic and past the No.1 Audi of Marcel Fassler to take the lead of the race.

Muscle Milk Pickett Racing had been leading the gas-powered P1 contingent until Lucas Luhr was sent from his pit stop with only three wheels properly affixed. The German would lose a lap while making the slow trek back to pit lane for a replacement.

2012 IndyCar Series Rookie of the Year Simon Pagenaud took over from Ryan Hunter-Reay in the No.552 Level 5 Motorsports HPD P2 car in the second hour. Despite Michelin making its return as a P2 tire supplier this weekend, the HPDs have been able to double- and triple-stint their tires so far. and rejoined behind his Level 5 teammate Scott Tucker in the No. 551.

By the end of the second hour it was Fassler leading from McNish under yellow, with Pagenaud heading the P2 class and Bruno Junqueira's No.9 leading PC.

The No.4 Corvette of Richard Westbrook held sway over the GT class, while Cooper MacNeil continued to control GTC in the No. 22.

***

The first hour of the 61st running of the Mobil 1 Twelve Hours of Sebring saw the expected dominance by Audi and more than a few problems for portions of the 42-car field.

Benoit Treluyer led his No.1 Audi R18 e-tron quattro away from teammate Tom Kristensen in the sister No. 2, one lap clear of Klaus Graf in the No.6 HPD ARX-03c.

The internecine duel between the turbodiesel Audis held an extra element of intrigue as the 2012-spec No. 1 proved to be faster than the 2013 iteration found with the No. 2. In race trim—at least during the first hour—Treluyer proved it was no fluke, putting more than 15 seconds between himself and Kristensen.

The aggressive behavior started early with Jon Bennett's PC car being clouted from behind by Antonio Garcia's Corvette C6.R GT car. The Spaniard would be penalized for avoidable contact, and later went behind the wall with electrical problems.

DeltaWing's race got off to a problematic start with reliability woes slowing the heavily revised P1 car. The car completed five laps before pitting to have a broken throttle body replaced on the Panoz-built 4-cylinder turbo.

Audi also got into the wheel-banging act, with Tom Kristensen nerfing the back of Anthony Lazarro's ESM HPD P2 car as the Dane went for a gap that lasted only a split second.

At the end of the hour the Audis led P1, with IndyCar Series champion Ryan Hunter-Reay leading P2 in the No. 552 HPD and Pierre Kaffer leading the Prototype Challenge in his No.81 ORECA.

The GT class was led by the Risi Ferrari of pole-sitter Gimmi Bruni with Cooper MacNeil heading the GTC class in his No. 22 Porsche.