The Thunder won their ninth in a row in what was the first meeting of the season between the NBA finalists from two years ago.
Oklahoma City scored the first two points of the evening and Miami then ran off 18 in a row. The Thunder, however, grabbed the lead by halftime and pulled away over the final two periods thanks to another big performance from Durant.
Durant scored 33 points, grabbed seven rebounds and added five assists. Serge Ibaka had 22 points and eight boards, while Jeremy Lamb had four of Oklahoma City's 16 field goals from 3-point range and finished with 18 points.
Both sides shot 51 percent from the field, but Miami turned the ball over 20 times and made 13 fewer 3-pointers than did the Thunder.
The teams will meet again in Oklahoma City Feb. 20.