Porsche held the lead halfway through the 83rd edition of the Le Mans 24 Hours Race early on Sunday, with the event so far involving a tight duel with Audi.
The two carmakers had swapped the lead during the gruelling endurance event, which was halted three times, but just after midnight (8am AEST), Porsche reclaimed the advantage thanks to Formula One driver Nico Hulkenberg.
Fellow former F1 star Mark Webber had earlier given Porsche a strong start but the Australian slipped back late on Saturday when he received a one-minute, stop-and-go penalty for overtaking under yellow flags during the third appearance of the safety car.
The Audis of Filipe Albuquerque and three-time winner Marcel Fassler were in second and third.
Earlier, Bill Ford – executive chairman of the Ford Motor Company and great-grandson of founder Henry Ford – had the honour of starting the race as French President Francois Hollande and other officials looked on.
Porsche are searching for their first victory in 18 years, while Audi are the dominant force having won 13 of the past 15 races.
More than 250,000 spectators are expected to take in the marathon race, which extends for 13,629 kilometres and concludes on Sunday.