Denny Hamlin won NASCAR's first race since 1984 when rain stopped the event with 20 laps remaining at Darlington Raceway.
The Daytona 500 winner was out front but out of fresh tires and trying to hang on when he got unintended help from Joe Gibbs Racing teammate Kyle Busch on Wednesday.
The reigning Cup champion caused Chase Elliott to crash eight laps earlier to bring out the caution.
A furious Elliott waited for Busch on the apron of the track and flipped Busch the middle finger as he passed. As NASCAR cleaned the track, it started to rain and the cars were called to pit road under red-flag.
It was an already active evening at "The Track Too Tough To Tame" as drivers were racing against the field and the weather. As the drivers sat in their cars waiting for NASCAR to pull the plug, a handful of Elliott's crew members sat on the pit wall starring down Busch.
One of Busch's crew members sat between them on the wall and NASCAR eventually ordered everyone back over the wall.
Eight minutes later, the race was called and Busch was greeted by Alan Gustafson, Elliott's crew chief and Busch's former crew chief when he drove for Hendrick Motorsports, for a conversation between two masked competitors. Busch immediately copped to the error.
"There's no question I made a mistake and just misjudged the gap," Busch said. "They're upset, they're mad. I'm not just going to fix and we're going to go have ice cream tomorrow. They're going to dwell on it and I'm sure there are repercussions of it I'm going to have down the road."
Hamlin had no choice but to stay out on the track, and his crew chief Chris Gabehart told him over the radio, "you ain't going to like it, but we're going to have to eat our vegetables here."
"You can do different things to make (the car) handle. We got it right."