NASCAR Sprint Cup champion Tony Stewart threw his helmet at the passing car of Matt Kenseth as a feud between the pair came to a head in Saturday night's Bristol race.
On lap 333 of 500, Stewart and Kenseth crashed while fighting for the lead shortly after a restart. The Stewart-Haas driver was attempting to pass the Roush Fenway Ford when the pair made contact and spun towards the inside barrier along the front-stretch.
Kenseth was able to continue, unlike Stewart, who then showed his anger by throwing his helmet at his rival's car as it came out of the pits.
"We weren't that great of a race car," said Stewart. "But we were definitely faster than that after that restart.
"I checked-up twice to not run over him and I learned my lesson there; I'm going to run over him every him every chance I've got from now until the end of the year, every chance I've got."
Kenseth said the incident with Stewart followed previous clashes at Sears Point and Indianapolis. He insisted he had tried to clear the air before Bristol but was snubbed.
"I don't really have anything bad to say about Tony," said Kenseth. "On the racetrack for years and years and years we've had tonnes of respect for each other and, for whatever reason this year, he ran me off the track at Sears Point and said he was sorry.
"It cost me seven spots in the finishing order and at Indy he was mad because he said I blocked him and I asked for five minutes of his time to clear the air and he wouldn't give it to me and pretty much just got cussed out and knocked my whole side off and put us in position to get wrecked.
"So I just said, 'OK, that's fine. I'm just going to race you the same way you race me,' and he showed me how he was going to race me down there, so I just did the same thing on the other end.
"If you look at it we did the exact same thing, it's just that he didn't lift so I don't really see where that's 100 per cent my fault or problem."
While Kenseth has already clinched a spot in this year's Chase despite his poor finish on Saturday night, Stewart dropped to 10th place in the standings. That means he has yet to secure a Chase place despite his three wins thus far.