These two had had enough of each other, and the tension boiled over.
Some last lap contact in Vegas led to contact of a different kind after the NASCAR Kobalt 400.
Joey Logano drove underneath Kyle Busch on the final lap and got loose, tapping Busch and sending him sliding into pit lane shortly before the checkered flag. Busch was not happy, and went to have words with Logano before a scuffle ensued.
The crews were able to separate the two but not before someone got a clean shot to Kyle's face.
Via Jalopnik, Busch said after the scuffle,
"I got dumped. Flat out got drove straight into a corner, It's how Joey races, so he's gonna get it."
We assume that means during the next race, because the only one who "got it" in this confrontation was Busch.