Los Angeles  - Kevin Garnett returned to the Boston Celtics' starting lineup, but in the end the All-Star forward was reduced to a cheerleader on the bench as the reigning NBA champions escaped with a thrilling road win.

Ray Allen scored 19 points, and Glen "Big Baby" Davis drained a key jumper with 5.7 seconds left as the Celtics welcomed back Garnett, with an emotional 80-77 victory over the San Antonio Spurs on Friday night.

Returning from a 13-game absence due to a strained right knee suffered on February 19, Garnett scored all 10 of his points in the third quarter, and grabbed four rebounds, while splitting his limited 14-minute stint evenly in the first and third periods as Celtics coach Doc Rivers promised.

"I felt really good," Garnett said. "Doc and I talked about strategy and minutes, and he said he'd go by the way I felt.""

Rivers would have liked to have the heart and soul of the Celtics' defense in the game down the stretch, but he kept Garnett on the bench as the nail-biter between the two most recent NBA Champions unfolded.

"We got Kevin Garnett sitting on the bench and I didn't want to look down there, because I wanted to put him in," Rivers said.

What was Garnett doing on the bench? "Cheerleading," Garnett joked. "I thought I did a good job of that. I just didn't have my pom-pons."

Frenchman Tony Parker scored 25 points, and Tim Duncan added 15 for the Southwest Division-leading Spurs (45-23) who blew the game by missing six consecutive free throws down the stretch.

"That's what the game is made up of," Spurs coach Gregg Popovich said. "They made mistakes; we made mistakes. Big Baby knocked down a jumper from the corner, and we missed six free throws in a row. It was a tough loss, but life goes on."

With the game squared at 74, usually reliable Michael Finley missed the go-ahead free throws with 2:32 left. After Kendrick Perkins' fade-away jumper gave the Celtics the lead for good, Parker failed on all four of his tosses on two trips to the stripe in the final 49 seconds.

"I was shooting normal free throws, like I did all year long," said Parker, an 80 per cent foul shooter this season. "It's just one of those games."

Boston's Paul Pierce penetrated the lane and spotted Davis in the left corner for the wide-open jumper to open up a 78-74 advantage with 5.7 ticks to go.

Finley nailed a three, but Pierce sank two free throws, giving the Celtics their third straight win in San Antonio after 17 consecutive losses. (dpa)