BOSTON -- The multitalented Toronto guards took over at just the right time on Friday night.

And Kyle Lowry and DeMar DeRozan had a little help from Norman Powell.

Lowry and DeRozan, one of the best guard combos in the league, and Powell brought their team back from a 10-point third-quarter deficit to a 101-94 victory over the Boston Celtics.

"DeMar made some big plays, but I thought Kyle and Norman Powell were the ones that killed us," said Celtics coach Brad Stevens, whose team played its second game without injured leading scorer Isaiah Thomas, blew a 14-point first-half lead and also led by 10 midway through the third quarter.

Lowry scored a season-high 34 points, 21 in the second half, and DeRozan added 24, 16 after halftime -- a night after the guard combo had 52 points in a home win over the Minnesota Timberwolves. Lowry iced the game with five free throws in the final 30.6 seconds.

"It was a very good team win for us," Lowry said. "Everyone stepped up tonight. We had a great team win tonight against a team -- they play extremely hard. They're missing their All-Star guard, but they play extremely hard and they play well together."

Powell, who starts when DeMarre Carroll sits on the back end of a back-to-back, added 20 points, Jonas Valanicunas grabbed 10 rebounds and Patrick Patterson had 10 boards and four assists off the bench.

"You've got to give that man a lot of credit," DeRozan said of Powell. "He can go a couple games without playing or only playing a few minutes. When his name is called to go out there and play, he shows a toughness.

"He's not sacred of the moment or nothing. You've got to give credit to him. It's great to have that type of player ready like that."

Powell, averaging 3.4 points per game off the bench, is at 15.6 as a starter.

The win, in the second half of a back-to-back (Lowry and DeRozan combined for 52 points on Thursday), was Toronto's eighth in the last nine games. The Raptors are now 16-7 this season.

Al Horford and Avery Bradley scored 19 points apiece for the Celtics, Horford added seven rebounds and six assists, and Terry Rozier had 12 points off the bench.

Asked about Horford's passing, Bradley said, "It makes it a lot easier. Al is a very smart player. We try to play through him because he makes the right play 99 percent of the time."

The Celtics (13-10) fired up 42 3-pointers, making 17 to match the franchise high, and missed seven of their 22 free throws. The Raptors (16-7) went 22 of 25 from the line, and Lowry and DeRozan combined to go 18 of 19.

"Obviously, if you look at it from our perspective, it's what went wrong, if you look at it from theirs, they ratcheted up the defense quite a bit," Stevens said of the third quarter. "It was hard for us to break their wall of defense."

The Celtics, who led by 14 after the Raptors' six-minute drought in the first half, were ahead by 10 when Lowry scored 12 points in the last 5:14 of the third quarter. He started his run with a four-point play and was also fouled on another 3-pointer, making all three free throws -- as the Celtics had their own six-minute drought.

Lowry and DeRozan combined for 24 points in the quarter and Powell scored his team's first eight points of the fourth quarter. The visitors built their lead to 11 and led 89-78 with 6:12 left.

The Celtics made their first four 3-pointers, the first two by Horford, and were 9 of 19 from behind the arc in the first half.

NOTES: Celtics G Isaiah Thomas missed his second straight game with a groin strain but is officially day to day. He will accompany the team on its two-game road trip, but there is no slated return to action. Before the game, he reacted strongly to talk-radio chatter that the team played better without him in the win in Orlando and said he is making sure he's healthy -- at the team request -- before he returns. ... Toronto coach Dwane Casey didn't like the way his team played defense in Thursday night's win over the Minnesota Timberwolves and saluted the Celtics before the game. "There's no question, they're right there with us," he said. "Talent-wise, they're one of the most talented teams in the Eastern Conference, so we know who they are and what they are." ... Former Celtics player Jared Sullinger still hasn't played a game for the Raptors, his new team, because of foot surgery. ... The Celtics visit Oklahoma City on Sunday. The Raptors, who just finished a six-game homestand, host the Milwaukee Bucks on Monday.