Cleveland Cavaliers head coach Tyronn Lue wants his team to play more physically after the Boston Celtics took control of the NBA Eastern Conference finals.

The Celtics claimed a 2-0 series lead over the Cavaliers with a 107-94 win in Boston on Tuesday.

Boston had six players with double-figure scoring as the topped the Cavs, despite a triple-double from LeBron James.

"They're playing tougher than we are. We see that," Lue said to reporters after the loss.

"They're being physical. They're gooning the game up and we've got to do the same thing. We've got to be tougher mentally and physically."

But, it was the Celtics players that were upset with a foul late in the fourth quarter.

With less than four minutes remaining at TD Garden and Boston leading by eight points, J.R. Smith pushed Al Horford in the back while he was attempting to finish an alley-oop.

Following the play, Boston guard Marcus Smart confronted Smith and the pair exchanged words.

Smith was called for a flagrant one foul after replay review.

Post-game, Smart said Smith's foul was "a dirty shot."

"We just can't allow that to keep happening," Smart said. "That's not the first time JR has done some dirty stuff, especially playing against us. It's like a bully.

"You keep letting a bully pick on you, he's going to keep picking on you until you finally stand up."

Smith shot 0 of seven from the field and failed to score in the game. Smart finished with 11 points and nine assists off the bench for Boston.