Ganassi #01 moves into Daytona lead

Entering the seventh hour of the race the leading Ganassi car lost the lead as Jamie McMurray got overtaken first by the #6 Michael Shank Racing Riley-Ford driven by AJ Allmendinger, and also by the #9 Action Express Riley-Porsche of Joao Barbosa.

Montoya was drafted back in the car after only an hour's rest to drive another stint in an effort to get Ganassi back in the lead. After just a handful of laps he was up front again, overtaking Michael Valiante at Turn 3. Barbosa kept in touch with Montoya, but suddenly the Colombian's hopes of a third Daytona 24 hours win went up in smoke.

A piston failed in the BMW Dinan engine just past midnight, and Montoya drove the car to the garage and into retirement. He said there were fears of an engine issue after the unit initially set for the race had to be changed on Friday when a leak was found.

"It was a sad to retire because we had a really good car," Montoya told AUTOSPORT. "All the drivers in the team were able to lead the race and we had a car to win it. But that's racing.

"On Friday we changed the engine for a new one but there was a problem with it and we had to get back to the testing one. We were a bit worried since then, but these things happen."

The Action Express Riley-Porsche inherited the lead after Montoya retired, but then the second Ganassi car started its surge. Scott Pruett ran a blistering pace in the early hours of Sunday and during the eleventh hour of the race he grabbed the lead just after setting what was then the fastest lap of the race, and following a pitstop from the leading #59 Brumos Riley-Porsche.

When Pruett finished his stint he held a solid lead, which Justin Wilson now maintains entering the second half of the race. The battle for victory has narrowed significantly through the night, and only the #9 Action Express Riley-Porsche driven by Mike Rockenfeller and the #6 Michael Shank Racing Riley-Ford with Allmendinger at the wheel run on the lead lap.

In the GT class there is a close battle between the #67 TRG Flying Lizard Porsche and Jan Magnussen's #57 Camaro as other contenders have dropped two or more laps down relative to the class leaders.