PITTSBURGH -- Leon Powe scored 17 points in the second half, including the go-ahead basket with just over two minutes left, to lead the Boston Celtics to a 90-86 win over the Cleveland Cavaliers in a preseason game Tuesday night.
Powe's dunk with 2 minutes, 17 seconds remaining put the Celtics ahead 85-84. Boston trailed 81-74 following an 8-0 Cleveland run early in the fourth quarter.
Powe, a third-year forward out of California, struggled in the first half with three fouls and zero points in two minutes before scoring nine points in the third quarter and eight in the fourth.
"Leon was good at the end," Celtics coach Doc Rivers said. "He got down on himself and really struggled for most of the game. He came back in the fourth quarter. It's a great lesson."
Ray Allen had 15 points in 23 minutes for the Celtics (3-1). Paul Pierce added 14 points and Kevin Garnett had 11 points and seven rebounds. Each of Boston's "Big Three" left the game for good midway through the third quarter.
"I thought our guys competed," Cavaliers coach Mike Brown said. "Once we settled down and took care of the ball and decided to defend, we put some stops together and executed well on the offensive end of the floor."
The Cavaliers are winless in three preseason games.
"The preseason is not about winning," James said. "You want to get some wins to feel good about yourself, but it's about learning."
Boston, which beat Cleveland in seven games in the Eastern Conference semifinals last season, has won both meetings in the preseason. The Celtics beat the Cavaliers 96-94 last Friday in Providence, R.I. The teams will open the regular season Oct. 28 in Boston.
The Celtics' Kendrick Perkins, making his preseason debut following offseason shoulder surgery, had five rebounds and four fouls in 21 minutes.
"I just got a little winded today, but I'm good," Perkins said. "I'm just happy to be back on the court."
Cleveland took a 49-47 lead just before halftime on James' final basket of the game. The Cavaliers outscored the Celtics 28-17 in the second quarter behind nine points from Gibson.
Allen scored 12 points on 5-of-7 shooting in the first quarter to help Boston go up 30-21. The Celtics trailed 9-5 before a pair of free throws and a lay-up from Pierce sparked a 15-2 run.
Rivers said Allen, Pierce and Garnett will see limited minutes and might not play at all against New Jersey on Thursday. ... Cavaliers F/C Ben Wallace remained in Cleveland to receive treatment for lower back tightness. ...Cleveland G/F Sasha Pavlovic (right ankle sprain) participated in the morning shootaround, but did not play in Tuesday night's game. ...Cleveland coach Mike Brown said before the game there is no timetable for the return of G Delonte West, who hasn't played this preseason because of undisclosed personal reasons. ...Tuesday night's contest was the first NBA game played at the University of Pittsburgh's Petersen Events Center.