Brooklyn beat Boston 95-83 in an Eastern Conference clash that turned nasty in the second quarter when three players were ejected after a skirmish.
Nets forward Kris Humphries sparked the melee when he gave Kevin Garnett a hard foul along the baseline.
The Celtics' Rajon Rondo retaliated by pushing Humphries, and the two tussled near the crowd as players from both sides converged on the scene.
Humphries, Rondo and Brooklyn forward Gerald Wallace were all thrown out of the game.
The ejection proved costly for Rondo, who saw his streak of 37 games with at least 10 assists come to an end. Rondo's run was tied for second longest all time in the NBA.
"I don't think anybody should be thrown out of a game, we all have to keep our emotions," said Boston coach Doc Rivers.
"I thought it was a bad foul (by Humphries), Rondo saw that and probably reacted - overreacted, obviously.
"At that point we're probably getting our butts kicked and were probably frustrated."
Joe Johnson scored a team-high 18 points as the Nets (10-4) stayed tied with the New York Kicks for the Atlantic division lead.