Boston, which couldn’t hold a 16-point lead in the first quarter, avoided its first six-game skid since dropping seven in a row from April 4-15, 2007.
Kyrie Irving returned from a bruised elbow that sidelined him late in the second quarter and led Cleveland with 24 points, 19 in the second half.
Irving hit two free throws with 1:21 remaining to give Cleveland an 81-80 lead. After Allen missed a 3-pointer, Garnett tipped Irving’s pass, leading to Allen’s dunk with 48.6 seconds left.
Irving drove down the lane and missed a layup with 27 seconds remaining. Garnett missed on Boston’s next possession, but grabbed his own rebound and was fouled by Antawn Jamison with 3.9 seconds to go. Garnett made both shots and the Cavaliers called a timeout, trailing 84-81.
Irving was fouled before he could get off a 3-point attempt and made both free throws with 3.5 seconds left. Allen hit two foul shots with 2.4 seconds remaining, and Anthony Parker’s 3-pointer at the buzzer hit the front rim.
A moment of silence was observed before the game for the victims of Monday’s shootings at Chardon High School, located approximately 30 miles from Cleveland. Three students were killed and two were wounded.
Celtics point guard Rajon Rondo was held scoreless for the first time since March 16 last season against Indiana, but had 11 assists.
The Celtics lead the Cavaliers by 2½ games for eighth place in the Eastern Conference.
Boston lost its final five games before the All-Star break, the last three by 15 or more points. It appeared the Celtics were headed to a blowout of their own as they dominated the first quarter, shooting 12 for 20 from the field. Their biggest lead was 28-12 on Garnett’s bank shot with 19 seconds left in the period.
Irving left the game with 3:41 remaining before halftime after taking a charge from Paul Pierce. Irving was taken to the locker room and returned to the bench with about two minutes to go, but didn’t play the rest of the half. Cleveland trailed 43-38 at halftime.
He returned to begin the second half and immediately made his presence felt. His 3-pointer broke a 53-all tie with 5:03 remaining in the quarter. Irving followed with a steal and a breakaway dunk to give Cleveland a five-point lead, its largest of the game.
Irving had six points in his last game before the All-Star break, tying his career low, and was 2 for 13 from the field. He scored 34 points and earned MVP honors in the Rising Stars Challenge on Friday.
Irving scored a game-high 23 points and hit a layup in the closing seconds to give the Cavaliers an 88-87 victory Jan. 29 in Boston.
Cleveland finished its franchise record nine-game homestand with a 4-5 record.
Celtics center Jermaine O’Neal missed his second straight game with a sprained left wrist. He remained in Boston and will be examined by doctors Wednesday.
NOTES: Boston F Brandon Bass, who had missed the past six games with a sore left knee, and center Chris Wilcox, who didn’t play in the final game before the All-Star break because of a strained right adductor, both returned. Bass scored 12 points while Wilcox had five points and a season-high 11 rebounds. … Parker returned after missing 12 games because of a lower back strain. He scored one point in 22 minutes. … Cavaliers G Manny Harris came off the bench in the first quarter, his first appearance since being signed to a 10-day contract last week. He had been playing with Canton of the NBA Development League.