The weather is Tony Stewart’s newest partner in his continuing domination of the Sprint Cup Series.

Stewart held the lead with 71 laps remaining Sunday as rain forced an early end to the Auto Club 400 at Auto Club Speedway. Since the race had reached the halfway point (100 laps), Stewart was declared the winner.

Rain showers put the race under caution with 75 laps to go and Stewart in the lead. He stayed on the track and kept first place until the field was red-flagged because of continuing rain a few minutes later. At 5:30 p.m. (ET), with rain continuing to fall and heavier weather moving in from the west, NASCAR officials called it a day.

Behind Stewart on the finish list were Kyle Busch, Dale Earnhardt Jr., Kevin Harvick and Carl Edwards.

Other than Stewart, the major beneficiary of the weather situation was Jimmie Johnson. His car began smoking with an oil leak during the caution period (the only one of the day), but he stayed on the track on the apron until the race was red-flagged, keeping 10th position. If the race had been resumed, he probably would have been in big trouble.

Stewart, last year’s champion, now has won seven of the past 15 Sprint Cup races over two seasons.

With rain pressing in near the perimeter of the speedway, Kyle Busch and Stewart wrestled for the lead as the race approached its halfway point.

After Stewart pushed past Busch to take the lead, Busch scraped the wall as he pursued the leader.

Busch was the dominant driver in the first quarter of the race, leading 49 of the first 50 laps. Pole winner Denny Hamlin, Busch’s Joe Gibbs Racing teammate, led the other lap.

All teams made their scheduled pit stops after the race reached halfway, with rain still threatening. Stewart returned to the lead at the end of the pit cycle.

Jeff Gordon lost a top-five spot during the pit-stop cycle when he was hit with a stop-and-go penalty for leaving his pit with a gas can (and the gasman) still attached to his car. After returning to the track, Gordon was in 19th, a lap down.

The race ran until lap 123 without a caution, then the yellow appeared when rain began falling in the turn-three area.

That left teams with a decision on whether to pit or stay on the track during the rain caution. Stewart, with the lead, faked toward pit road but pulled back onto the track. Hamlin pitted from second place and fell to 11th after his stop.

Hamlin wanted to be in good shape if the race resumed, but the pit stop cost him nine positions when the weather worsened.

With a sixth-place finish, Greg Biffle stayed atop the Sprint Cup point standings. Harvick is second, seven points back, and Earnhardt Jr. is third.

Mike Hembree is NASCAR Editor for SPEED.com and has been covering motorsports for 30 years. He is a six-time winner of the National Motorsports Press Association Writer of the Year Award.