The Audi R18 e-tron quattro of Andre Lotterer, Benoit Treluyer and Marcel Fassler had triumphed in a dramatic Sllverstone Six Hours race, regarded as a warm-up for the famed Le Mans 24hrs in June.
But in post-race scrutineering the winning Audi was excluded, stewards deciding that a skid block on the flat plank running under the car was worn by more than the 5mm permitted by the regulations.
This handed the win to the Porsche 919 Hybrid of Neel Jani, Romain Dumas and Marc Lieb, which had finished 46 seconds behind the Audi, while the third manufacturer contesting the flagship Le Mans Prototype LMP1 category, Toyota, claimed second with its TS050 Hybrid driven by Mike Conway, Stephane Sarrazin and Kamui Kobayashi.
The results remain provisional, however as Audi has lodged an appeal against its exclusion.
With just over two hours of the race gone, however, second driver Brendon Hartley made contact with a GTE Porsche while lapping it and was launched violently into the barriers, the car rearing on its side and almost rolling.
Hartley was later reprimanded by stewards after they decided he had attempted to lap the GTE car in an unsafe manner.