James Harden scored 40 points but the Rockets lost for the first time since Jan. 26 at New Orleans.
Jonas Valanciunas had 14 points and 10 rebounds as the Raptors won their seventh straight in a matchup between the respective conference leaders.
The Rockets shot 9 for 27 from 3-point range, matching their fewest made 3-pointers of the season.
Houston tied it at 102 on Harden’s 3 with 2:10 remaining, but DeRozan restored Toronto’s lead with a jump shot with 1:49 left.
Paul missed a go-ahead 3 with 14 seconds to play, then fouled Lowry in the scramble for the rebound. Lowry made both, giving the Raptors a 106-102 lead with 10 seconds to go.
Gordon answered with a 3, making it a one-point game. Houston fouled Valanciunas, who made a pair to put Toronto up by 3 with 5.4 seconds to go.
Harden got the final shot but his deep 3 from the edge of the center court circle went short, giving the Raptors the win.
Lowry connected on his first five shots and scored 13 points in the opening quarter as Toronto led 32-16. The Rockets missed eight of their first 10 field goal attempts and shot 6 for 21 in the first, missing all five 3-point attempts. It was Houston’s lowest-scoring first quarter of the season and just the second time they’ve failed to score at least 20 points in the first.
Harden scored nine points in the second but the Rockets continued to struggle from long range, making one of four 3-point shots. DeRozan had seven points for the Raptors, who led 58-43 at halftime.
Houston’s only lower-scoring first half this season was a 39-point effort in a Feb. 26 win at Utah.
The Rockets were 1 for 12 from 3-point range before Harden drained back-to-back shots with 2:48 left in the third. Harden scored 14 in the third, overcoming nine points from Lowry, as Houston cut the deficit to 83-75 after three.
Raptors: Forward OG Anunoby (sprained right ankle) missed his fourth straight game. … G Delon Wright (sprained right big toe) was unavailable after leaving Wednesday’s win at Detroit. Wright initially suffered the injury in Tuesday’s home win over Atlanta.
Rockets: Visit Dallas on Sunday. Houston has won seven straight in the series, its third-longest streak all-time.
Raptors: Visit New York on Sunday.
More NBA basketball: https://apnews.com/tag/NBAbasketball