Audi wrapped up the 2013 World Endurance Championship crown two rounds early despite losing a weather-hit contest to rival Toyota at Fuji.
Heavy rain ensured that all three attempts to get the 6 Hour race underway were eventually called off, with a total of 16 recorded laps having been driven behind the Safety Car.
The yellow flag running between the first and second stoppages proved decisive, as the lead Audi, driven by Andre Lotterer, was pitted to rectify engine problems.
This allowed the Toyota of local hero Kazuki Nakajima to take over the top spot and the eventual victory; Audi's first defeat of the season.
Nakajima's co-drivers Alexander Wurz and Nicholas Lapierre also shared the victory, despite not driving in the race.
The Lotterer Audi was eventually classified down in 26th, one place ahead of Anthony Davidson's Toyota, which joined the race at the back of the field after a miscalculation saw the Briton miss the pre-race pit exit cut-off.
Loic Duval drove the #2 Audi to second place. With half points awarded to all drivers in each car, Duval and co-drivers Allan McNish and Tom Kristensen now hold a commanding 40.75 point lead over stable-mates Lotterer, Benoit Treluyer and Marcel Fassler with two rounds remaining.
The weather proved a blow to Australian John Martin's hopes of gaining season honours in the LMP2 class.
The Australian watched on as co-driver Mike Conway cruised to second behind the points leading Oak Morgan-Nissan of Bertrand Baguette, Martin Plowman and Ricardo Gonzalez.
Martin's entry had missed pole on Saturday by just 0.08s despite a mid-session spin from Conway ensuring the former Australian Formula Ford Champion had to complete his run with damaged tyres.
The season will conclude with races in China (November 9) and Bahrain (November 30).