PROVIDENCE, R.I. -- LeBron James only needed two preseason games to get back into a groove.
The Cleveland star scored 12 points in the first quarter, finishing with 15 in 13 1/2 minutes on Friday night to help the Cavaliers open an early lead before the Boston reserves took over and led the NBA champions to a 96-94 victory.
"It was good. I got out there and got a good rhythm," said James, who played just eight minutes and failed to make a basket in Cleveland's first preseason game. "We got into a good rhythm, and we played well."
Tony Allen scored 25 points, and Leon Powe hit two free throws with 13.6 seconds left to put Boston ahead just as Jed Lowrie's sacrifice fly gave the Red Sox a 1-0 lead in the AL playoffs against Tampa Bay.
Celtics coach Doc Rivers checked on the baseball score with reporters sitting courtside. Updates were also played on the arena scoreboard, and fans begged Rivers to call a timeout down the stretch, so they could watch more of the baseball game.
Allen made 13 of 16 free throws.
"He's going to get to the line," Rivers said. "He attacks off the dribble, he's aggressive, and he's tough to guard."
It was 94-all when Tarence Kinsey missed a jumper with 15 seconds left, and Lorenzen Wright fouled Powe going for the rebound. Powe's free throws gave Boston a 96-94 lead, and Bill Walker blocked Jawad Williams' shot at the buzzer.
The Cavaliers thought he was fouled, but no one really wanted to see a preseason game go into overtime, so no one really complained.
The Celtics are making the rounds in New England this exhibition season, visiting Amherst, Mass., on Wednesday before dropping down to Rhode Island and then up to New Hampshire. The crowd of 9,444 was about 1,000 short of a full house even though the game was up against the opener of the AL championship series.
"I really hadn't planned on playing Kevin and those guys at all tonight," Rivers said. "But I thought because we're right here down the road the fans needed to see them a little bit. And they got a chance to see the other guy, LeBron, who is pretty good, too. I thought they got their money's worth."
After spending his summer at the Olympics helping the United States win the gold medal, James played just eight minutes in Cleveland's exhibition debut on Tuesday, a 104-84 loss to Toronto.
Rivers is also wary of his players' workload, even though none of them played in Beijing. Boston's season didn't end until June 17 after an 82-game regular season and 26 playoff games, including the seven-game victory over Cleveland in the Eastern Conference semifinals.
The budding rivalry might have explained an unusual burst of effort for an exhibition game, with the Cavaliers taking a 37-28 lead after one quarter of All-Star game-style play.
"We scored a lot," Cavs coach Mike Brown said. "But I didn't see much defensive intensity out there."
Celtics center Kendrick Perkins did not play because of surgery for the left shoulder injury he sustained in Game 4 of the NBA finals against the Los Angeles Lakers. Rivers was back after missing Wednesday's exhibition opener, a 98-92 loss to Philadelphia, to attend to a family matter in Orlando, Fla.
Cavaliers guard Sasha Pavlovic did not travel with the team to Providence to continue treatment on his right ankle. He experienced a mild sprain during practice Wednesday and is day-to-day.