DeMar DeRozan's teammates know exactly what to do whenever the Raptors guard gets into a groove.

Just let him go.

DeRozan poured in 34 points, including 18 in the third quarter alone, to lead Toronto to a season-high sixth straight victory, 115-109 over the visiting Boston Celtics on Wednesday.

Toronto was 16-for-22 from the floor in the third, outscoring the Celtics 40-26 for a season-high in a single quarter. DeRozan's solid play had a lot to do with that.

"Give him the ball and get out of the way, give him the ball and get out of the way," Kyle Lowry said of his game plan whenever DeRozan gets hot. "He's going to shoot his little Kobe Bryant fadeaways and he's going to make them. Just give him the ball and get out of the way.

DeRozan, who has 64 combined points over Toronto's last two games, also had six assists and was 8-for-9 from the free-throw line on Wednesday.

Jonas Valanciunas had his eighth double-double of the season with 19 points and 12 rebounds and Luis Scola added 18 points for the Raptors (27-15). Terrence Ross chipped in with 14, including four three-pointers, and Lowry had 14 to help Toronto improve to 19-8 against NBA Eastern Conference opponents this season.

Isaiah Thomas led the Celtics (22-21) with 21 points and 10 assists, Avery Bradley had 19 points and Canadian Kelly Olynyk contributed 18.

Former Raptor Amir Johnson, in his first game back in Toronto since signing a free-agent deal with the Celtics this off-season, had two points as Boston lost for the fifth time in six road games.

Video tribute

The Raptors played a video tribute early in the game for Johnson, who spent six seasons with the team, and it was met with a standing ovation from the sellout crowd of 19,800.

"It was amazing," Lowry said of the fan reaction. "I knew it would be an ovation like that and it was well deserved. He put his blood, sweat and tears into this organization and into this franchise and I think the fans, the organization, everyone appreciated what that meant."

'It doesn't matter, we got a win ... and we're happy with that.' - Raptors' Kyle Lowry after being told the Celtics scored 18 points on 13 Toronto turnovers

Johnson called the video tribute "pretty unique."

"I thought it was pretty awesome," he added. "I was teary-eyed a little bit. That was cool."

The Celtics tied the game 105-105 on a Bradley jump shot with 3:20 left. But Lowry and Ross hit threes on consecutive possessions moments later to restore Toronto's lead.

Boston scored 18 points on 13 Raptors turnovers and hit 12-of-26 three-pointers.

"It doesn't matter, we got a win," Lowry said of his team's defensive lapse. "At the end of the day we got a win and we're happy with that.

Boston outscored Toronto 35-21 in the second quarter and took a 62-56 lead into halftime.

"It's important that you win ugly," said Raptors coach Dwane Casey. "We could easily have been on the other side of that. We know we're not doing some things well, turning some balls over. They were making their threes, we were missing our wide-open threes. We have to find other ways to win."

Toronto went on a 9-0 run midway through the first quarter en route to a 35-27 lead after 12 minutes. Scola led the way with 11 points and DeRozan poured in 10 as the Raptors outshot Boston 20-8 in the paint.