The Thunder maintained a half-game lead over San Antonio in the race for the No. 1 seed in the West. Oklahoma City has two games remaining and San Antonio has three.
Portland held a one-point halftime lead, but was then overwhelmed by the Thunder in the third quarter 26-7.
Portland was led by Will Barton with 18 points.
Dennis Rodman pledges to end trips to North Korea
Scarlett Johansson steps out with fiance after pregnancy reveal