They trimmed the Spurs lead in the series to 2-1.
Backup point guard Reggie Jackson started for the Thunder in place of shooting guard Thabo Sefolosha and also scored 15 points. He was 6-for-13 overall but just 1-for-6 on threes.
Russell Westbrook led all scorers with 26 points on 8-for-19 shooting while also grabbing eight rebounds and handing out seven assists.
The Spurs just had three players in double figures.
Sixth man Manu Ginobili led the way with 23 points, but 20 of those came in the first half. Ginobili was just 1-for-3 with three points in the critical second 24 minutes. Tim Duncan (16 points) and Kawhi Leonard (10 points) were the only other Spurs to make it into double digits.
The Spurs have now lost eight straight games in Oklahoma City (regular season and playoffs), the longest active streak against any team.