Less than two minutes into the third quarter, the Cavs used a 7-0 run to get out to an 11-point lead.
Both players were ejected from the game.
Ibaka was battling Chriss for positioning to receive a full-court pass with one second remaining in the quarter. A Raptors spokesman said Ibaka was reacting to something Chriss said to him after the Toronto player was knocked to the floor.
The Raptors have recently been alternating between looking like a dominant team that has figured out how to play within their game and looking like a team struggling to find the motivation to play, and Monday night in Cleveland, that second group showed up for most of the night.
With the loss, the Raptors now sit at a record of 48-20 and are still ranked second in the Eastern Conference.
Leonard, averaging 27.1 points going into the game, hasn't appeared in more than two consecutive games since playing in five straight from January 25 through February 5.
Quotable - Coach Larry Drew, on his rookie point guard's performance on Monday ... Ibaka would lose about $149,000 for every game he misses.
Ibaka fell to the ground and Chriss looked at him while saying something, then turned around and ... you know how the story goes.
Kevin Love tallied his sixth double-double since the All-Star Break - finishing with 16 points and a game-high 18 boards. McCaw appeared in three games with the Cavaliers earlier this season.
"I didn't see much of it, to be honest", Nurse said. 'We certainly don't want that in the game.