TORONTO -- DeMar DeRozan led the Raptors with 41 points in a 114-106 victory over the Boston Celtics on Tuesday night, but Toronto coach Dwane Casey was even more impressed with his guard's play on the boards.

With Patrick Patterson still feeling the effects of a knee injury that sidelined him for four games, and with Jonas Valanciunas getting double-teamed, DeRozan stepped up and collected 13 rebounds, including 11 defensive boards.

"He's a tough kid, he didn't grow up in Compton for nothing," Casey said. "He's a tough kid. More than anything else, the 41 points is nice, but 13 rebounds, the 11 defensive rebounds when we needed it. ...

"DeMar came in and got some big rebounds, tough rebounds, so that was impressive. That was more of a sign of grit and grind as much as the 41 points."

The Raptors (25-13) closed out the fourth quarter on a 19-4 run to pick up their third consecutive home victory over Boston. The Celtics (23-15) saw their four-game winning streak end.

Valanciunas added a career-high 23 rebounds and 18 points. Kyle Lowry chipped in with 24 points, nine assists and four rebounds in the win.

"You have to give (Boston) a lot of credit," said DeRozan, who shot 16 of 29 from the floor and 8 of 9 from the foul line. "That's a hell of a team, a talented team, and they play extremely hard. They're right behind us, so that was one of those games coming into tonight -- the vision game -- and so many elements came into play tonight and we had to definitely bring our 'A' game against (them) tonight, and we did."

Isaiah Thomas led the Celtics with 27 points and seven assists. Guard Marcus Smart continued to fill in nicely for the injured Avery Bradley, contributing 16 points, five assists, four rebounds and four steals.

Gerald Green and Al Horford added 14 points apiece for Boston, and Canadian Kelly Olynyk chipped in with 13 points. Horford grabbed a team-high nine rebounds.

"The fact that DeRozan was able to get into the teeth of our defense and make those tough shots, I think that's what took something from us," Horford said. "Guys started stepping up. Valanciunas was in there cleaning stuff up and despite all that, I thought we were in a good position where we could have made plays.

"We just didn't make them down the stretch."

The Raptors, who trailed by as many as 16 during the third quarter, used a late 7-0 run to pull to within five.

A Thomas layup pushed the Celtics' lead to 84-80 to close out the third period.

"The last six minutes of the third crushed us, and the last six minutes of the fourth," said Celtics coach Brad Stevens. "I think it was like 42-15 or something in those timeframes.

"I thought we got probably a little too careless with the ball, and that hurt us."

Smart paced the Celtics with 14 points in the first half as Boston held a 55-46 lead at the break.

After shooting 8-for-22 in the opening quarter, the Celtics were hitting at a 70 percent clip with 2:31 to play in the half.

DeRozan had 10 first-half points, while Lowry added 10 points and five assists for the hosts.

Raptors led 23-18 after one period, paced by six points and nine rebounds from Valanciunas.

For the game, both teams shot 47.1 percent from the floor.

NOTES: Celtics G Avery Bradley missed his second consecutive game due to an strained right Achilles tendon. Coach Brad Stevens had no update on Bradley's status for Wednesday when Boston visits Washington. ... Boston C Tyler Zeller (sinus infection) missed his fourth game. According to Stevens, Zeller saw "a bunch of different doctors over the last couple days.". ... Raptors F Patrick Patterson, who returned to the lineup on Sunday after missing four games with a strained left knee, made his first start of the season Tuesday. He finished scoreless in 21 minutes. ... Tuesday was the second of four meetings between the division rivals. Toronto won the first meeting 101-94 at the TD Garden on Dec. 9.