Townley was the aggressor, coming down the track after he and Gallagher exited their wrecked trucks on Lap 154, grabbing Gallagher in a headlock and throwing him to the ground.
They clinched and tossed each other around several times, falling to the pavement again, and then Townley landed a flurry of punches to Gallagher’s head, while Gallagher appeared to landed just one punch in retaliation.
That late-race incident was their second of the night. Contact with Gallagher earlier in the race caused Townley to crash.
None of the safety workers interceded, prompting a lengthy delay before a NASCAR official arrived on scene and broke up the pair.
The race was red flagged for a third time so that the track could be cleaned up.
Both drivers were taken to the infield care center to be examined for injuries — in separate ambulances.
Christopher Bell won the race.