Custer, who was angry about Reddick making contact with him, approached his rival after they parked in the pits. Custer put a hand on the shoulder of Reddick, who responded by grabbing Custer with both hands (watch the video above).
The drivers both fell to the ground as they were swarmed by members of both teams. Neither driver seemed to be hurt, though Reddick had a red mark above his right eye.
“I was just frustrated that he can’t keep his car on the bottom and then runs us up into the wall,” Custer told NBC Sports. “If he wants to wreck cars and put them in the wall, that’s fine, but when it affects me, I’m not going to be very happy with him.
“I don’t know. I just went over to talk to him and say that and put my hand on him, and he just went berserk. I thought we had a good car and a shot to win.”
As he approached Reddick, Custer addressed him with “You can be a dumb (expletive).”
“I understand Cole’s frustration 100 percent,” Reddick told NBC Sports. “We’re trying to lock ourselves into Homestead, and he came up to talk after the race. He put a hand on me, I put a hand on him back, and that’s just how it’s going to be if we’re going to have a conversation that way.
“I’m out of breath. Had a fight there with some people, and it was a little bit of fun. I think a lot of Cole and his driving ability.”
Reddick finished runner-up Saturday to Brandon Jones, who won but already had been eliminated from the playoffs and wasn’t eligible to advance to the championship round. Custer finished 10th.
With two races remaining in the Xfinity playoffs at Texas Motor Speedway and Phoenix Raceway, Reddick and Custer both are comfortably in position to reach the title race at Homestead-Miami Speedway.
Custer is 38 points ahead of the cut line, and Reddick is plus-37. Christopher Bell, who crashed with leader Chase Briscoe when he ran into the rear of the lapped car of Garrett Smithley, remained the championship leader at 49 points ahead of Briscoe, who is two points behind fourth-ranked Justin Allgaier
“It was just heat of the moment,” Reddick said of the scuffle. “We’re pissed off. I’m sure we’ll talk about it here soon, maybe today, tomorrow.
“I hate that it happened to him, but we’ll try and move forward. Both of us have a lot left to lose in this deal, and if we take each other out, neither one of us get to Homestead, and I feel we both deserve to be there.”
A Stewart-Haas Racing spokesman said Reddick and Custer talk led later in the garage as their cars went through postrace inspection.
Custer also was involved in a notable altercation after a truck race three years ago at Canadian Tire Motorsport Park, where he tackled John Hunter Nemechek in anger after they collided on the last lap while racing for the lead.
Nemechek made light of that situation while Custer did postrace interviews Saturday (see the :50 mark of Dustin Long’s Twitter video below).