The defending Rolex 24 champions have rallied from a huge deficit at Daytona International Speedway.
The No. 60 Michael Shank Racing entry, anchored by NASCAR driver AJ Allmendinger, was seven laps down after an early steering problem Saturday.
But after several caution flags overnight, including a two-hour slowdown because of heavy fog, Shank's Ford Riley was just a lap back with six hours to go in the twice-around-the-clock endurance race.
The No. 01 BMW Riley of Chip Ganassi Racing, anchored by veteran Scott Pruett, was back out front with six hours to go. Pruett is trying to tie Hurley Haywood's record of five Rolex victories.
The other Ganassi entry, though, has fallen way back. NASCAR regular Jamey McMurray hit a wall leaving the pits overnight, causing the team to lose several laps.