"I had to throw the block there," Logano said. "That was a race for the lead. I felt if the 14 got underneath me, that was going to be the end of my opportunity to win the race, so I was just trying to protect the spot I had."
Stewart ran over to Logano's car and confronted him after the race, shoving the younger driver — who then threw a water bottle at Stewart, the veteran said — before teammates pulled them apart.
Stewart was replaced by Logano at Joe Gibbs Racing when Stewart left to drive for his own team starting in 2009.
"What the hell do you think I was mad about?" Stewart asked before providing a colorful series of expletives.
Roger Penske, in St. Petersburg, Fla., for the IndyCar race, firmly backed Logano, who was hired by Penske Racing last September.
"I think it's great," Penske said. "I think (Logano and Hamlin) have got to work it out themselves. He knows what the big picture is. To get yourself knocked off the track every other weekend, you'll never get in the Chase and have a chance to win the championship, so I think cooler heads will prevail. He said, 'I'm going to be around a long time,' was his comment to me."
Busch took advantage of his remarkable stroke of luck to pick up JGR's first victory at Fontana, the only track where the team had never won. Toyota also got its first Fontana win.
"They forgot about me. I knew they were going to," Busch said. "We had a good run on the top side, and they were messing with each other so bad that they took each other down. I was just hoping I could get by before they took me with him."
Earnhardt turned in yet another solid race and passed Brad Keselowski atop the points standings despite falling from third to 22nd late in the race with a dismal pit stop.
Carl Edwards came in fourth, with Kurt Busch fifth. Keselowski finished 23rd after starting at the back, missing the top five for the first time all season.
Kyle Busch's victory was his 25th in NASCAR, completing his ninth career weekend sweep after his Nationwide Series victory Saturday. He ended a 31-race Cup winless streak since last April at Richmond.
"Oh, by the way, I won the race today," Busch said. "That might be a story. I'm sure it's not, though."
AP Auto Racing Writer Jenna Fryer in St. Petersburg, Fla., contributed to this report.
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