KANSAS CITY, Kan. — The race started with six of the Chase for the championship drivers separated by just 28 points in the standings.

When it finally ended — under caution and cut short because of darkness — the Chase field had imploded and Greg Biffle was the only driver certain he won Sunday's race at Kansas Speedway.

"Let me tell you what, he didn't win the race," said fifth-place finisher Jeff Gordon. "Clint Bowyer is the winner of this race in my opinion, no offense to Greg Biffle."

It was that kind of day at Kansas Speedway, where Biffle scored his first win of the season by winning a race that was stopped twice for rain delays, was shortened 85 miles because of darkness, ended under caution and had six Chase drivers finish 29th or worse.

And when Biffle's sputtering car slowed before the finish line, title contenders Clint Bowyer and Jimmie Johnson passed him and both believed they finished ahead of him.

"I don't know what happened, (he) didn't cross it the way I thought you were supposed to," said Kansas native Bowyer, who had to settle for second place on his homestate track.

"I know they're not going to pull him out of Victory Lane."

Johnson, who finished third to reclaim the points lead, said Biffle wasn't the winner.

"The biggest question mark right now is what goes on with (Biffle)," he said. "He clearly ran out of gas and I feel terrible for those guys. But if you can't maintain pace car speed, then the guys that can finished ahead of you."

But Biffle, who ended a 28-race winless streak with the victory, angrily dismissed their criticism.

"Their opinion really doesn't count, as far as I'm concerned," he said. "They're probably thinking, 'Oh, it ran out of gas, I coasted across the line, everybody went by me, I went into the grass and then they pushed it to Victory Lane.'

"That's not the case. The car runs right now ... you can go and start it. (NASCAR) told me not to start it. I was unbuckling, and trying to save my gas, because I knew the race is over. The field's frozen. The caution's out. And I didn't know they were going to go by me. So should I have bumped the clutch again, gave it a little more juice, so nobody would roll past me coming to the stripe?"

NASCAR spokesman Ramsey Poston said Biffle was the winner because the race ended under caution, the field was frozen and passing is not allowed under caution.

Rain caused two delays totaling almost three hours, Kyle Busch was wrecked early by the driver who got him fired from Hendrick Motorsports, and two-time series champion Tony Stewart gambled twice — the first one put him in position to win, and the second one took him out of contention.