Kyle Busch took the lead early and held it after 100 miles of the Auto Club 400 in Fontana.
There was no doubt that the drivers had a sense of urgency when the race started as the sky grew darker. Denny Hamlin won the first lap but soon gave up the lead to Busch on the second lap. By the sixth lap Busch had even extended his lead to almost a second.
Tony Stewart, who started ninth, made a move as the race progressed. By the 18th lap he had moved up to fourth. By the 19th lap he passed Greg Biffle to move into third. On the 28th lap, Stewart moved up one more position and was 1.3 seconds behind Busch.
Meanwhile, the temperature was cooling down as the rain approached and the pit crews and drivers were trying to figure out how the track conditions would change.