TORONTO -- The Toronto Raptors are on a roll.
They extended their winning streak to a season-best six games Wednesday with a 115-109 victory over the Boston Celtics.
And with five games left on a seven-game home stand, they have an excellent opportunity to build something special.
Guard DeMar DeRozan led the way with 34 points in a game that was tied at 105 with 3:20 to play before the Raptors went on a 6-0 run.
"When it's going you really don't pay attention to it until after the fact and realize everything was feeling good," DeRozan said.
"We kind of hung around and actually played pretty well for a large part of the game," Celtics coach Brad Stevens said. "I think the story of tonight is the first and third quarters, 75, points. You can't win that way against a good team,"
The Raptors shot 55.4 percent in the game and Celtics were at 50.6 percent although things tightened up in a 19-19 fourth quarter.
"(Defense) is one thing we understand that we have to clean up, get better at it and be more conscious of it coming out of the gate," DeRozan said.
Center Jonas Valanciunas added 19 points --going 9-for-9 from the field -- and 12 rebounds for the Raptors (27-15).
Boston forward Jae Crowder cut the Raptors' lead with 1:05 to play, but DeRozan came back with a 19-foot pullup jumper to restore Toronto's lead to four points with 46.9 seconds left in the game.
After a Boston miss, Toronto point guard Kyle Lowry made two free throws with 14.8 seconds to play to make the lead six points and clinch the game.
Forward Luis Scola scored 18 points for Toronto, forward Terrence Ross contributed 14, and Lowry scored 14 points and had eight assists.
Guard Isaiah Thomas scored 21 points and had 10 assists for the Celtics, who lost their second game in a row.
"He's so talented," Lowry said of Thomas. "He gets to the basket, he draws fouls and he shoots the ball very well. He's No. 2 in the league in fourth-quarter points and scoring so he's got it going late."
The Raptors defense has been loose for the past two or three games.
"We have lost our defensive mojo a little bit," Raptors coach Dwane Casey said. "We made some adjustments tonight and that helped us a little bit. ... We scored 40 points in the third quarter, we are going to find our offense at some point. It may not be pretty but we will find it. We have to maintain our defensive focus."
"We got our opportunities again," Olynyk said. "We're right there in every game, we've just got to make sure we get over the hump. They ran pick and rolls really well. Lowry runs the pick and roll really well. DeRozan's tough. ... Valanciunas obviously. There's just a multitude of things."
The Raptors opened a 13-point lead in the first quarter. They led 35-27 at the end of the quarter thanks to 11 points from Scola and 10 from DeRozan.
The Celtics went on a 9-0 run late in the second quarter to take a six-point lead. They entered the second half with a 62-56 advantage led by Crowder's 12 first-half points. Scola led all first-half scorers with 15 points.
The Raptors regained the lead, 70-68, on a 3-pointer by Lowry with 7:59 to play in the third quarter. There were five lead changes and six ties in the quarter before Valanciunas gave Toronto a five-point lead on a cutting layup with 1:24 left in the third.
DeRozan's turnaround jumper bumped the lead to seven points. Toronto led 96-90 after the three quarters.
Thomas cut the lead to two points on a jumper with 6:39 left, but DeRozan and forward Patrick Patterson scored to boost the Raptors' lead to six points.
A running layup by Thomas reduced the lead to two points. After a Raptors miss, Bradley tied the game at 105 on a 19-foot pullup jumper with 3:20 to play.
Lowry responded with a 3-pointer. After Olynyk scored for Boston, Ross hit a 3-pointer and Toronto led 111-107 with 2:16 to go.
The Celtics were left to lament the opening quarter of each half. "We were just getting beat to balls left and right," Stevens said. "We obviously got a rhythm offensively during the other times of the game that we didn't have during those times."
NOTES: Former Raptors F Amir Johnson returned to Air Canada Center for the first time since signing with the Celtics as a free agent in July. He spent six seasons in Toronto. "Great fan base," he said of Toronto. "I always said it's not just the city; we had the whole country behind us. It was pretty cool going on a couple runs and having the country cheering for us." ... The Raptors won the first meeting of the season between the teams, 113-103 on Oct. 30 in Boston. ... Toronto recalled F Anthony Bennett, F Bruno Caboclo and G Delon Wright from Raptors 905 of the NBA Development League. ... The Celtics return home for a game on Friday against the Chicago Bulls. The Raptors will play the third game of seven straight at home on Friday against the Miami Heat.