Reigning European Le Mans Series champions Mathias Beche and Pierre Thiriet claimed victory in the Imola 3 Hours for the TDS Racing squad.
Beche, who was racing the team's ORECA-Nissan 03 for the first time this season, and Thiriet were on top in a closely-fought battle with the Jota Sport when the Simon Dolan lost time when he spun the British team's Zytek-Nissan Z11SN in the final hour. That allowed Thiriet to take a clear victory, nearly 50 seconds up on the Signatech Alpine team's ORECA-Nissan 03 shared by Nelson Panciatici and Pierre Ragues.
Beche said: "Pierre did an amazing job today, I am very proud of him. He had the pace on Dolan, so we deserved to win today."
The Morand Racing Morgan-Judd/BMW LMP2 came home third in the hands of Franck Mailleux and Natacha Gachnang, a lap down on the top two.
The Swiss team inherited the position when the Greaves Motorsport Zytek-Nissan shared by Tom Kimber-Smith and David Heinemeier Hansson was given a one-minute stop-and-go penalty for a pitlane infringement at its final pitstop.
The Greaves car ended up fifth behind the Race Performance ORECA-Judd/BMW shared by Patric Niederhauser and Michel Frey.
The Jota Sport Zytek, in which Olivier Turvey had led throughout the first stint, did not finish. Alternator failure resulting from Dolan's spin caused the car to stop out on the circuit with four minutes to go.
The new-for-2013 Ram Racing Ferrari team took its first victory in only its third race, and second in the ELMS, after Matt Griffin and Johnny Mowlem dominated the GTE class.
Griffin battled with the ProSpeed Porsche 911 GT3-RSR of Patrick Long for the first hour, only losing the lead on his final lap of his opening stint with a fuel-surge problem. He was subsequently able to move his Ferrari 458 Italia into a clear lead when Patrick Milesi took over the Belgian team's car.
Victory in the one-make LMPC class went to the Team Endurance Challenge ORECA-Chevrolet FLM09 shared by Gary Hirsch and Paul-Loup Chatin, which led the category from start to finish.
The Russian SMP Racing team's Ferrari 458 Italia shared by Kirill Ladygin, Victor Shaitar and Fabio Babini claimed GTC honors.