Westbrook missed his first five shots but scored the last seven points of the first half as the Thunder turned a three-point deficit into a four-point lead. He scored 18 in the fourth quarter, including eight straight during a 10-0 run that flipped a 104-100 deficit into a six-point lead.
Rookie Domantas Sabonis topped his career high by halftime and finished with 20 points for Oklahoma City, which had lost three of its previous five games. Enes Kanter had 20 points off the bench.
Isaiah Thomas had 34 points and 10 assists and Al Horford scored 23 points for Boston, which had won a season-high four straight games.