Durant converted 6-of-7 shots from 3-point range and scored a dozen points in the final 3 1/2 minutes of the game to give the Thunder their fourth consecutive victory.
The win gave Oklahoma City a one-game lead in the Northwest over second-place Portland. The Trail Blazers have lost back-to-back games since their five-game winning streak came to an end.
LeMarcus Aldridge scored 29 points and pulled down 16 rebounds for Portland. Wesley Matthews scored 21.
The game featured 13 lead changes and 45 rebounds for each team. Oklahoma City pulled away in the home stretch with Durant leading the way while the Blazers managed just one field goal in the final 3:45.