Audi Sport Team Phoenix is out front of the Nürburgring 24, as the German endurance classic reaches the one-quarter mark and into the night-time hours.
The No. 1 Audi R8 LMS of Chrisopher Haase, Christian Mamerow, Rene Rast and Markus Winkelhock holds a two-minute lead over the No. 30 Frikadelli Racing Team Porsche 911 GT3 R in second overall.
The Frikadelli entry lost time in the sixth hour due to an unscheduled pit stop for a slow puncture, although it still remains ahead of the No. 19 BMW Sports Trophy Team Schubert BMW Z4 GT3, which runs in third.
The Porsche enjoyed time out front in the third hour, as well as hard-fought battle with the No. 1 Audi, Nos. 19 and 26 BMWs and both Black Falcon Mercedes-Benz SLS AMG GT3s through the opening hours.
However, not everyone came through unscathed, with tricky conditions claiming a few pre-race favorites.
The second hour saw a brief period of rain, which caught out a handful of cars, including the No. 20 BMW Sports Trophy Team Schubert BMW of Claudia Hurtgen, who slammed into the wall and was later retired.
There were also issues for the No. 85 Bentley Continental GT3 of Guy Smith, who made contact with the No. 44 Falken Motorsports Porsche and was stranded on track in the third hour, requiring a lengthy tow back to the paddock for repairs.
One hour later, it was the No. 29 Audi Sport Team WRT entry of Pierre Kaffer to run into trouble, as the German made contact with another car, requiring a new splitter and bumper. It came after a flash fire for the car while refueling in the second hour.
Adam Christodoulou, meanwhile, slowed on track in the fifth hour when the left-rear wheel of his No. 2 Black Falcon Mercedes-Benz SLS AMG GT3 came loose. He too, became stranded on track, despite efforts to re-attach the wheel.
Christodoulou was running third at the time prior to the incident, which appears to be the end of the race for the former overall race-winning squad.