TORONTO (AP) The Toronto Raptors ended their four-game losing streak with a focused defensive effort.
Kyle Lowry scored 10 of his 19 points in the fourth quarter, James Johnson had 15 points and 10 rebounds and Toronto beat the Boston Celtics 109-96 on Saturday night to snap its longest skid of the season.
''I thought our defensive mojo was back,'' Raptors coach Dwane Casey said. ''I saw guys moving their feet, cracking down, rebounding, doing the things we needed to do with activity and anticipation.''
Lou Williams scored 19 points and Jonas Valanciunas and Amir Johnson each had 15 to help the Raptors improve to 6-0 against Atlantic Division opponents and avoid losing consecutive home games for the first time since March 2014. Toronto is 15-4 at home this season.
The Raptors trailed by seven points after one quarter but turned the game in their favor by outscoring Boston 63-39 in the second and third.
''We just got more defensive-minded,'' Lowry said of the turnaround. ''We weren't really worried about the offensive end, we knew the shots would fall. We put a real good emphasis on defense tonight.''
James Johnson started for the sixth time this season and the first time since Dec. 30 at Portland. Landry Fields had started the previous three games, but Casey wanted to make a change.
''James gave us a boost off the bench but now ,out of necessity, we had to have him in that first group,'' Casey said.
Kelly Olynyk scored 23 points and Avery Bradley had 17 for the Celtics, who wrapped up a three-game trip with their ninth loss in 11 games. Boston, which lost in overtime at Indiana on Friday night, was playing for the third time in four nights.
Jared Sullinger scored 13, Marcus Smart had 12 and Brandon Bass 10 for the Celtics, who fell to 2-4 on the second night of back-to-backs.
Celtics forward Jeff Green was inactive for the second straight night and a person familiar with the situation told The Associated Press on Saturday night that Boston, Memphis and New Orleans have agreed on a five-player trade that would send him to Memphis. The person spoke on condition of anonymity because the trade hasn't been announced and formal approval by the NBA is not expected until Monday morning.
Trailing by 17, Boston opened the fourth with a 12-3 run, cutting it to 85-77 at 8:56. Lowry scored five points as the Raptors regained control with a 12-1 run over the following four minutes, putting the game out of reach.
''They're at a different level than we are right now,'' Celtics coach Brad Stevens said of Toronto. ''We need to play better if we want a chance to win against a team of that caliber in this building.''
Toronto started the game by missing 10 of its first 13 field goal attempts and trailed 26-19 after one, the ninth time in 11 games they've faced a deficit at the end of the first. The Raptors have not led after one quarter since Dec. 28 at Denver.
Williams scored eight points in the second and Amir Johnson added six as the Raptors outscored Boston 28-17 to lead 47-43 at halftime.
Boston led 55-53 after a jump shot by Sullinger at 8:47 of the third, but Toronto responded with a 23-6 run over the next six minutes, with the Celtics calling timeout after a basket by Lowry put the Raptors up 76-61 at 2:35. James Johnson scored 10 points in the third and Valanciunas had eight as Toronto took an 82-65 lead into the fourth.
Toronto faced a Boston lineup without guard Rajon Rondo for the first time since April 4, 2006. Rondo was traded to Dallas on Dec. 18.
Olynyk's 23 points were the most he's scored in three regular season visits to his hometown. ''It's always nice to come up here and play well in front of your country,'' he said. Olynyk and the Celtics will be back in Toronto on April 4.
Celtics: F Jae Crowder made his second straight start. ... G Jameer Nelson (right ankle) missed his fifth straight game. ... Boston fell to 4-12 on the road.
Raptors: Terrence Ross has made at least one 3-pointer in a career-high 13 consecutive games. ... Toronto is 14-0 when holding opponents below 100 points. ... Actress Susan Sarandon attended the game.
Celtics: Host Pelicans on Monday night.
Raptors: Host Pistons on Monday night.