Franck Montagny leads Le Mans after the first hour as drama struck the Peugeot challenge following a pit collision between two of the 908 Hdi FAP turbo-diesel coupes.
Peugeot appeared to have a clear advantage over its rival Audis after Pedro Lamy and Alex Wurz demoted Allan McNish's R15 TDI to fourth in just two laps.
But as the first round of pit stops took place, Lamy's second-placed car was released into the path of Jean-Christophe Boullion's Pescarolo-run Peugeot and the pair collided. The #17 machine was dragged into pit garage, but Lamy returned to the track.
A subsequent left-rear puncture ripped a massive hole in the back of the factory car on the Mulsanne straight, prompting a safety car period that took the race through the first hour.
"I had a pit stop and when I started coming out Boullion was coming in," said Lamy. "He touched me on the rear and I had a puncture. When asked about the blowout while returning to the pits, he added: "There was nothing we could do, it was too long [to get back]. I've no idea how long it will take to fix, hopefully just a few minutes."
While chaos raged in the French manufacturer's pit as the significant damage to the #7 Peugeot -- including a broken oil pump -- was assessed, Audi brought McNish and Mike Rockenfeller in for their regular stops, allowing them to take second and fourth during the safety car period, split by the impressive Stefan Mucke's Aston Martin.
The blue and orange British sports cars look to have the pace to chase the Audis at least, as Darren Turner ran fifth, ahead of Marc Gene in the second of the Peugeots. Montagny, meanwhile, was well clear up at the front, caught behind a the second safety car which gave him an automatic 1m45s lead.
Emmanuel Collard established a lead for Essex Porsche in the LMP2 class, pursued by the similar RS Spyder of Team Goh's Seiji Ara.
Jan Magnussen led GT1 for Corvette, while Patrick Long leads the GT2 class for Porsche ahead of Jaime Melo after a fabulous four-car dice that included Jorg Bergmeister and Marc Lieb -- the last of which picked up a puncture of his own and has dropped away from the leaders in class.
Of the cars with early problems, the most significant was Alex Premat's factory Audi which ran off the road at Indianapolis on the third lap. It is currently a lap off the lead in 23rd place.
Harold Primat brought #009 Aston Martin in to the pits in need of a new alternator -- as did the GT1 JetAlliance Aston.