DeRozan, who netted 12 points in the fourth quarter, was 14-of-27 from the court and 12-of-17 from the free throw line to power the Raptors to their eighth home win in a row over the Rockets.
Atlantic division leader Toronto improved to 44-30, one game behind Chicago for the third-best record in the Eastern Conference.
Southwest division leader Houston fell to 50-24, level with Memphis for the division lead and the second-best record in the Western Conference.
Toronto’s Jonas Valanciunas scored 15 points and grabbed nine rebounds while Amir Johnson pulled down a game-high 16 rebounds for the Raptors.
The Rockets, who saw their four-game win streak snapped, were led by James Harden with 31 points.
Dwight Howard sat out after playing Sunday. He has been on limited duty since returning last week from a knee injury suffered in January. – Agence France-Presse