CLEVELAND • The Boston Celtics could not hold on to a late lead, and Avery Bradley could not hold on to the ball. Ultimately, it did not matter.

He recovered in time to make a three-pointer at the buzzer on Friday, and the Celtics stormed out of Quicken Loans Arena with a stunning 104-103 victory over the Cleveland Cavaliers in the National Basketball Association.

The visitors rallied from five points down in the final 18.6 seconds after blowing a seven-point lead with four minutes left.

Bradley's shot against the team that swept the Celtics in the first round of the play-offs last season bailed them out.

"In the big picture, it does count as one, but it gives you a sense you're improving and getting better," Celtics coach Brad Stevens said.

"For us, it would have been disappointing to lose that lead and not come out with a win.

"They made huge plays late in the game, but our guys stayed poised.

"To score five points inside eight seconds is a good deal."

The Cavs seemed to have the victory sealed, when guard J.R. Smith grabbed an offensive rebound off forward LeBron James' missed three-pointer with 22 seconds left.

Guard Kyrie Irving made a pair of foul shots for a four-point lead, but Smith fouled Evan Turner while the Boston swingman was driving for a basket with four seconds left.

Turner's hoop pulled the Celtics within 101-103, but he missed the free throw, and the ball trickled out of bounds off the Cavs.

It gave possession back to the Celtics with one final shot to win it.

Forward Jae Crowder inbounded to guard Isaiah Thomas, who started to drive before spinning and passing back towards Bradley.

Bradley momentarily fumbled the pass but recovered in time to get the shot off with guard Iman Shumpert - the Cavs' best perimeter defender - standing in front of him.

"I knew it was there," Bradley said. "It's a great feeling."

James scored 30 points, including 13 in the fourth quarter, but was so upset he put in a rare post-game workout before speaking with reporters. "It's how we lost. It hurts," he said. "It's been a while since I felt like this."

When asked if he thought the defence covered Bradley's shot well, he said: "No."

Thomas scored 22 points and Turner had 19 points, 12 rebounds and six assists off the bench for the Celtics.

Smith scored 20 points before fouling out on the critical play that sent Turner to the line.

Irving had 19 points and six assists for the East-leading Cavaliers (35-14), who fell to 5-3 under new coach Tyronn Lue.

"There were more than a few mental mistakes going down in those last final seconds until that buzzer went off," said Irving. "It was just a few bad bounces that obviously can be corrected by us."

Forward Kevin Love's run of bad luck against the Celtics (30-22) continued, when he left the game late in the third quarter with a bruised thigh.

He was bumped by guard Marcus Smart under the basket with two minutes left in the quarter and dropped to the ground.

Love was writhing in pain on the baseline for a few moments and had to be helped to the bench before limping to the locker room.

"Probably for 10 minutes there it was a dead leg," said Love, who underwent season-ending surgery on his dislocated left shoulder after Game 4 against the Celtics in April.

"I don't know what it will feel like (Saturday), but I'm optimistic it's just a thigh bruise, nothing else."

He finished with 10 points and five rebounds, although he had eight points and four rebounds after the first quarter.

REUTERS