With Tracy McGrady on the bench with a sore left shoulder, the Rockets got 18 from Rafer Alston and 16 from Luther Head in winning their fourth straight. Houston is in fifth place in the tightly bunched Western Conference, but just two games behind conference-leading New Orleans.
Kevin Durant scored 26 for Seattle, which has lost seven out of eight.
Seattle owned a five-point lead after one period, but managed just 11 points in the second quarter and was not a factor in the final half.
Houston has captured 18 of its last 19 home games. Seattle has won just six road contests all season.