Clarkson hit 5 of 6 3-pointers - he was 6 for 12 overall from the floor - and was perfect on six free-throw attempts for the Golden Hurricane (16-11, 9-4 Conference USA), who have won nine of their past 11 games and defeated Rice for the 12th straight time.
The Owls (15-12, 6-6) got 11 points from Connor Frizzelle and 10 from Omar Oraby.
Rice was within 49-47 after Frizzelle hit a pair of free throws with 7:47 remaining. But Idlet hit six straight free throws and Clarkson followed with two more as the Hurricane pulled away down the stretch. Idlet had 10 points during the final surge, including a fast-break dunk with 1:02 remaining that closed out the scoring.