AUBURN HILLS, Mich. -- Al Horford looked like a $113 million player in his return to action Saturday.

Boston's prized free agent acquisition scored on a putback with 1.3 seconds remaining and made a game-clinching block, giving the Celtics a 94-92 victory over the Detroit Pistons at The Palace.

Horford piled up 18 points, 11 rebounds, five assists, three blocks and two steals for Boston (7-6). The power forward, who signed a four-year, $113 million maximum contract this offseason, missed the previous nine games while recovering from a concussion.

"I felt really good," he said. "It was just very frustrating these past few weeks, dealing with a lot of different things. Finally I was at the point where I felt good enough to play."

That was an understatement as he delivered a game-changing performance. Horford's go-ahead basket came after Jae Crowder missed a 3-point shot and Marcus Smart missed a putback.

"The credit goes to Marcus," Horford said. "Those are championship plays, winning plays that he made right there. He crashed the glass hard and the ball just fell to me. I just put it back in and that was that."

Following a Detroit timeout, he sealed the victory by blocking an Aron Baynes shot just before the final buzzer.

"He had nowhere to go," Horford said. "I was just right there. The main thing was don't let him get the shot off."

Crowder, who sat out eight games with a left ankle sprain, had nine points and four assists.

Celtics point guard Isaiah Thomas supplied 24 points and eight assists and backcourt partner Avery Bradley chipped in 13 points.

Andre Drummond led the Pistons (6-8), who lost at home for the first time this season, with 20 points and 17 rebounds. Drummond surpassed the 4,000-rebound mark for his career.

Marcus Morris had a team-high 24 points, Tobias Harris contributed 19 and Ish Smith added 12 for Detroit.

"It's extremely tough," Harris said. "We were in position to come out of here with a victory but it went the other way. We can't let them get two extra shots off that but it's something to learn from."

Pistons coach Stan Van Gundy regretted taking out Drummond for the final 30.5 seconds.

"I'm kicking myself right now," said Van Gundy, whose team lost its third straight. "If he had been in the game, we probably would have got the rebound and we're probably still playing."

Both teams were coming off double-digit losses Friday night. The Celtics lost to Golden State 104-88 and the Pistons were blown out by Cleveland 104-81.

The Celtics opened the second half with an 8-2 spurt to take a 58-49 lead. Detroit responded with an 11-0 run, capped by a Drummond alley-oop dunk.

Detroit took its biggest lead at 71-64 on Smith's coast-to-coast layup. The Celtics then finished the quarter on a 7-2 run to make it a two-point game entering the fourth.

Neither side led by more than four points in the fourth. Morris shot over Thomas on a switch to tie the game at 84 with 2:52 remaining. Bradley responded with a layup before Kentavious Caldwell-Pope drained his only bucket, a 3-pointer, to give Detroit a one-point edge.

After Horford and Drummond traded baskets, a Thomas layup with 1:10 left gave Boston a 90-89 lead. Thomas tossed in a pair of free throws with 30.5 seconds left for a three-point advantage.

Harris knocked down a corner trey with 23.2 seconds left to tie it. Horford then scored his game-winner.

"We didn't call a timeout in the last four minutes, they just played," Celtics coach Brad Stevens said. "I felt like we had a good lineup in there to score and get to the basket, those types of things. Guys made the right reads and right plays."

NOTES: Detroit coach Stan Van Gundy pondered a lineup change but decided to put off any moves. "My staff's point was to take tomorrow and think about it," he said. "Right now, having time to think is hard when ... you're just playing all the time." ... Boston was completing a home/away back-to-back, one of eight such back-to-backs on its schedule. ... Celtics PG Isaiah Thomas was averaging 9.0 fourth-quarter points, second only to Oklahoma City's Russell Westbrook (9.8). entering the game. ... Pistons C Andre Drummond has 122 double-doubles since the 2014-15 season, the most in the league. ... Detroit won six of the last eight meetings at home. ... The teams next face each other Nov. 30 at Boston's TD Garden.