Andre Lotterer has had to tread delicately in the #2 Audi through the 22nd hour at Le Mans after rain enveloped the circuit. He now leads Simon Pagenaud in the #9 Peugeot by 27 seconds as the French team exerts its advantage of numbers by splitting its tyre strategy among its remaining cars.
What started as a mere sprinkle built gradually to a steady drizzle without quite tipping the balance in favour of intermediate tyres. The track became extremely slippery but Anthony Davidson revelled in the conditions, unlapping himself from Lotterer, who slithered briefly off the circuit as he let the #7 Peugeot past.
Nicolas Minassian pitted the third-placed #8 Peugeot and took on intermediates but saw no immediate benefit - indeed, he was outpaced by his team-mates - and by the time Lotterer made his own routine stop at 40 minutes past the hour the rain had abated a little.
Lotterer departed without changing tyres and over the following laps his #2 R18 looked to have an increasingly tenuous grip on the track as the rain returned with a vengeance. Even so, when Davidson pitted to hand over to Marc Gene, Peugeot wheeled out fresh slicks and sent the Spaniard on his way.
The battle for fifth place between the ORECA Peugeot and Henri Pescarolo's open-topped petrol-powered LMP1 swung dramatically as first ORECA then Pescarolo's cars encountered trouble. Loic Duval had a trip through the gravel at Indianapolis early in the hour and then lost the engine cover as he limped the Peugeot back to the pits.
That handed the advantage to Emmanuel Collard in the Pescarolo, but when the rain was at its heaviest Collard lost control in the Porsche Curves and hit the wall. That leaves the Rebellion Lola of Jeroen Bleekemolen as the leading petrol-powered runner in seventh overall.
Tom Kimber-Smith's Greaves Zytek continues to lead LMP2, and lies eighth overall, despite the Briton temporarily beaching the car in the gravel during the rain shower.
The second-placed #26 car lost considerable time at the beginning of the hour when Franck Mailleux picked up a puncture on the pit straight and had to crawl around the length of the course before pitting, then he spun at the PlayStation chicane just before the turn of the hour. The Signatech Nissan is now just a lap ahead of Christophe Bouchut in the delayed #33 Lola.
Tom Milner hunted down and passed the struggling #51 Ferrari of Toni Vilander in his #73 Chevrolet Corvette to take the lead in GTE Pro and now leads by 27s, while third-placed Joey Hand has a two-minute advantage over the Porsche of Wolf Henzler.
Julien Canal still has a lap in hand over Larbre team-mate Jean-Phillipe Belloc in GTE Am.
- Jan Magnussen lost control of the GTE Pro-leading #74 Chevrolet Corvette and crashed into the #63 Proton Porsche during the 17th hour, putting both cars out.
- Jean-Christophe Boullion crashed the Rebellion Lola-Toyota in the 14th hour at the Porsche Curves. He had been running eighth at the time of the shunt.
- Mike Rockenfeller was taken to hospital following a frightening accident that totally destroyed the #1 Audi in the seventh hour of the race. The German had been running third when he made contact with a GTE Ferrari at kink after Mulsanne. Audi later confirmed that the German would be kept in overnight for observation but that he was okay.
- The #3 Audi of Allan McNish crashed out of the race in the first hour having just taken second position. The Scot collected the #58 Luxury Racing Ferrari in the right-hander after the Dunlop Bridge. The heavy impact destroyed the car and McNish was taken to hospital for precautionary checks, but was later released with an all-clear.
- Both Aston Martin AMR Ones ran into trouble on the first lap of the race. Darren Turner spinning with mechanical trouble and Adrian Fernandez stopping out on the Mulsanne. The #007 car of Turner was recovered to the pits where it was discovered an alternator belt tensioner was to blame.