The #3 Audi R18 TDI held the lead at the halfway stage of the Sebring 12 Hours in the hands of Timo Bernhard.
The German, who shares the car with Romain Dumas and Loic Duval, had just taken the lead from the sister car driven by Rinaldo Capello as the opening round of the new FIA World Endurance Championship hit the six-hour mark.
The #2 Audi, in which Capello is joined by Allan McNish and Tom Kristensen, had led for the majority of the first half of the race. The car was nearly a minute ahead in Kristensen's hands after two and half hours, at which point a series of safety-car periods wiped out that cushion.
Kristensen reasserted his advantage and was 10 seconds ahead of Duval when he handed over to Capello. The Italian held off Bernhard until the closing stages of his stint.
The #1 Audi driven by Benoit Treluyer, Andre Lotterer and Marcel Fassler fell off the lead lap when an electrical glitch hit the car at the start of the fifth hour. Treluyer came slowly into the pits before the problem was resolved by hitting the electrical reset button, but the Frenchman had caught the Joest Audi team by surprise and a pit infraction meant he had to return to the pits to take a stop-go penalty.
The problem reoccurred late in the sixth hour and the car was taken back to the paddock to investigate what were described as gear selection issues.
The best of the Rebellion Racing Lola-Toyotas and the Pickett Racing Honda Performance Development were battling over third place nearly two laps back from the Audis. Nick Heidfeld in the Lola held a narrow advantage over Simon Pagenaud in the HPD.
The LMP2 class was led by Joao Barbosa in the remaining Level 5 Motorsports HPD ARX-03b. The Portuguese held a 30s advantage over Stephane Sarrazin in the Starworks HPD.
Seven cars were on the lead lap in a frenetic battle in the GTE class. Tommy Milner topped the order in the best of the Chevrolet Corvette C6.Rs from Marc Lieb in the Felbermayr-Proton Porsche 911 GT3-RSR.