Serge Ibaka scored all 15 of his points in the first half for the Thunder.
Oklahoma City went on 14-4 run in the first quarter to take a 21-14 lead and was never threatened after that. The spurt was capped by consecutive dunks from Nick Collison and Durant. Collison, a former star at Kansas, drew loud ovations all night.
The Mavericks pulled to 80-71 on a jumper by Bernard James with 5:48 to play, but Dallas was held to only one point over the next four minutes.