Tim Duncan scored seven of his 19 points in overtime as San Antonio beat Oklahoma City 112-107 in game six Saturday to set up an NBA finals rematch with the Miami Heat.
Duncan also added 15 assists and power forward Boris Diaw came off the bench to score 26 points for the Spurs, who won the Western Conference final series four games to two.
San Antonio will host the first game of the National Basketball Association finals on Thursday against the two-time defending champion Heat, who beat them in seven games last season.
The Spurs won despite playing the second half of game six without star guard Tony Parker, who played just 19 minutes Saturday before leaving the game with a foot injury.
Kevin Durant finished with 31 points and 14 rebounds for the Thunder, who had their nine-game home win streak against San Antonio snapped.