Audi's motorsport boss Dr. Wolfgang Ullrich believes the firm's ninth Le Mans win this year was the toughest so far.

Peugeot looked like it had beaten Audi for a second straight year, but as the 908s all suffered failures, Audi's revised R15 TDI Plus came through to take a one-two-three, led by the No. 9 car of Mike Rockenfeller, Romain Dumas and Timo Bernhard.

"At the beginning it was a little unlucky for us, but at the end it worked out fine," said Ullrich. "It's a great reward for all the work everyone has done. I think this has to be the hardest Le Mans we've ever done."

Ullrich was congratulated by his Peugeot counterpart Olivier Quesnel straight after the race, and he paid tribute to Audi's archrival and the camaraderie's between the two teams.

"I think that they know we have done a great job," said Ullrich. "In sport when someone wins, someone else loses, but when the loser comes and congratulates the winner it is very sporting. That is what we did last year and that's what Peugeot has done this year.

"It has been a fantastic battle. We've invited the Peugeot guys to a party tonight and we hope they will come."