The Nuggets had won six in a row. Oklahoma City boosted the NBA's best record to 31-8 by capturing its fifth straight.
Westbrook scored 32 points, hitting 12-of-20 from the field as part of Oklahoma City's 51-percent shooting performance. The Thunder opened a 16-point lead after one period and had a 25-point cushion heading into the final quarter.
Denver was led by 16 points from Kosta Koufos. The Nuggets' starters produced just 46 points.