The Rockets scored 73 points in the first half and then disappeared over the final two quarters.
Houston produced only 10 points in the third period and then scored nine in the fourth while Oklahoma City was making up a 14-point halftime deficit. The Rockets had won their previous three games.
Durant went to the foul line 20 times and made 18 of those attempts, finishing with 36 points. Reggie Jackson added 23 points and Serge Ibaka had 21. Those three scored all but 24 of Oklahoma City's points.
Houston went scoreless for the first 3:43 of the third period, missing its first nine shots of the quarter.
Oklahoma City took the lead for good in the opening minute of the fourth quarter on a 3-pointer by Jeremy Lamb.