BOSTON -- A loud fire alarm rang through TD Garden minutes after Friday night's game.

It came about an hour late for the home team.

It came after the Golden State Warriors put on a third-quarter clinic -- at both ends of the floor.

"I think defensively the third quarter was fantastic," Kevin Durant said after the Warriors outscored the Celtics 31-9 in the third en route to a 104-88 rout of the Boston Celtics. "That's high-level defense. We're flying around, helping each other, getting our hand on basketballs, getting out on transition.

"It was incredible to watch. We've got to continue to build on that. Offensively, another 30-plus assist night it was good for us."

The Celtics went 2-for-17 in the quarter.

Ahead by seven at halftime, the Warriors went on a 24-3 run -- capped by an 18-0 streak -- to break open the competitive game and power to their sixth straight victory.

Boston, still playing without the injured Al Horford (concussion) and Jae Crowder (ankle), were in the game and trailed 55-48 at the break. The Warriors then went wild and improved to 10-2.

Klay Thompson scored 11 of his 28 points in the quarter.

Durant, seriously courted by the Celtics before signing with Golden State, scored 23 points and added 10 rebounds and seven assists, and both he and Thompson sat as the Celtics made their little run.

Naturally, Durant was booed -- loudly during the pregame introductions and then every time he touched the ball.

"I didn't care," he said. "I'm always motivated to play, so, no, I was cool."

Steph Curry avoided a season-low in scoring when he hit a 3-pointer and another basket late, finishing with 16 points (his low was 13), while Draymond Green had 11 points, eight rebounds and eight assists in the win.

Curry, who also got a technical foul, was 7-for-16 from the floor, 2-for-10 from 3-point range and also missed three layups.

Down 30 early in the fourth quarter, the Celtics were able to cut their deficit to 12 with 1:50 left.

Isaiah Thomas led the Celtics (6-6) with a season-low 18 points (his previous low was 23), while Avery Bradley scored 17.

After the game, Thomas, who sat out much of the fourth quarter and logged 27:35 (with a game Saturday night), said he wasn't thrilled his team threw in the towel.

Thomas was asked about Warriors big man Zaza Pachulia imitating Durant after hitting an outside shot to cap an 18-0 run to blow open a competitive game.

"Yeah, but at that point the game was turned around," Thomas said. "I guess we gave up. Coaching staff as well. We start subbing. It was bad ... we gave up.

"We went into panic mode for whatever reason, and that's what happened. So I'm upset with that."

As far as his new teammate's impression of him, Durant said, "It was terrible. It was horrible. We'll talk about that."

The Warriors led by 30 in the third quarter, becoming the first visiting team to lead by 30 since last season, when Durant and the Oklahoma City Thunder did it.

Celtics guard Marcus Smart, who missed the first three games of the season with an ankle sprain, suffered a left ankle contusion and left the game in the third quarter. He had 10 points and two steals.

"They said he bruised it, I don't know exactly how or what happened," said Boston coach Brad Stevens, who said trainer Ed Lacerte indicated the injury wasn't serious.

On the final play of the first quarter, Boston rookie Jaylen Brown threw up a 3-pointer that missed and it looked like he might have been fouled by Andre Iguodala as the buzzer sound. The play ended and the officials then looked at the video -- and determined Brown had kicked Iguodala for a technical foul. Thompson hit the free throw to give his team a three-point lead after one.

Brown and Terry Rozier both scored 11 points off the Boston bench.

NOTES: C Al Horford (concussion) and F Jae Crowder (ankle) were still missing from the Boston lineup, but both will accompany the team on the three-game road trip that starts in Detroit Saturday night. ... Warriors coach Steve Kerr, before the game, on Celtics fans perhaps booing F Kevin Durant for going to Golden State and not Boston: "Is that true, are they upset? My guess is it's all in good fun. You come to a game and you're a Celtics fan, and you know you were close and you didn't get him. So what do you do? You boo him. I think most of that stuff is tongue-in-cheek. People come to the game to be entertained, let their emotions out." Durant was booed lustily. ... The Warriors are at Milwaukee Saturday night. ... The Celtics handed the Warriors one of their nine regular season defeats last season and lost the other matchup in double overtime -- but Golden State has won four straight at TD Garden.