Audi took the lead of Le Mans for the first time with 10 hours to go after the leading Toyota retired after stopping on the circuit with electrical problems.
Kazuki Nakajima was at the wheel of the TS040 Hybrid when it slowed at Arnage and could do nothing as the second-placed #2 Audi of Benoit Treluyer passed him to take the lead, soon followed by Brendon Hartley in the #20 Porsche 919 Hybrid.
The retirement was the first by a Toyota in all three races in this year's World Endurance Championship although the first two races had been six hours each and the TS040s had not been put under the pressures of 24-hour race conditions.
As Nakajima brought the LMP1-H prototype to a halt, glum team members in the pit garages looked on in disbelief.
Nakajima had been partnered by Stephane Sarrazin and Alexander Wurz, who tweeted his agony as the lead their car had held for more than eight hours evaporated:
I am devastated and want to cry! Leading the LeMans 24h race for 14h... pushing every inch along the way... and now technical breakdown :-(— alex wurz (@alex_wurz) June 15, 2014
The retirement meant the LMP1-H class was reduced to six cars from eight following the #3 Audi's retirement earlier and threw the race wide open although Treluyer held a three-lap advantage over Hartley with the #1 Audi of Lucas Di Grassi a further lap behind.
With more than nine hours still to go, all teams know that anything can still happen and even the second Toyota of Anthony Davidson, Sebastien Buemi and Nicolas Lapierre might still have a part to play. However, it would need to rely on others falling by the wayside as it lies 12 laps off the lead car.
Earlier, Davidson had prioritised winning points for the FIA World Endurance Championship.
“The task now for the #8 is to score as many points as possible for the World Championship," he said. "We are pushing as hard as we can and we will try to get the best result possible."