Tim Duncan had 19 points and 15 rebounds for the Spurs, who will host Game 1 on Thursday night as they try to avenge last year’s heartbreaking seven-game loss.
Boris Diaw scored 26 points for the Spurs, who won despite point guard Tony Parker missing the entire second half and overtime with left ankle soreness.
Russell Westbrook had 34 points, eight assists, seven rebounds and six steals, and Kevin Durant added 31 points and 14 rebounds for the Thunder. Oklahoma City overcame a 12-point deficit in the fourth quarter to force overtime.
Kawhi Leonard added 17 points and 11 rebounds, and Manu Ginobili chipped in 15 points and six rebounds for the Spurs, who pulled this one out after losing in overtime in Game 6 against the Heat in the NBA Finals.
San Antonio went on to drop Game 7, but put that loss behind and had the NBA’s best record this season.
“It’s unbelievable to regain that focus after that devastating loss we had last year,” Duncan said.
In overtime, Duncan’s shot from the baseline rattled in to give the Spurs a 110-107 lead with 19 seconds to go.
Durant missed a good look at a 3-pointer, and the Spurs rebounded and went to the line. Diaw missed the first and made the second free throw to make it a four-point lead for the Spurs. Westbrook missed a wild 3-pointer, and Spurs wrapped it up.
San Antonio led by 12 early in the fourth quarter, but the Thunder chipped away at the free throw line after getting the Spurs into foul trouble. Back-to-back baskets by Westbrook and Durant cut San Antonio’s lead to 93-91 with 4:01 to play, leading to the frantic final minutes.
Durant made two free throws to tie the score at 97 with 58 seconds left. San Antonio attacked, but Serge Ibaka blocked Ginobili’s shot at the rim — replays showed the ball hit the backboard first and should have been a goaltend — and Derek Fisher rebounded.
Durant quickly attacked the hoop out of a timeout and made a layup with 32 seconds to play, finally giving the Thunder the lead at 99-97.
Ginobili came back with a 3-pointer with 27 seconds to play, putting the Spurs back up 100-99.
Durant lost the ball, and San Antonio came up with it, forcing the Thunder to foul. Ginobili made the first and missed the second free throw with 15.9 seconds to play.
Westbrook was fouled on a drive with 9.3 seconds to play. He made both free throws to tie the score at 101. Ginobili’s fadeaway at the free-throw line against Westbrook missed, and the game went to overtime.
NOTES: The Spurs had just two assists and missed all five of their 3-point attempts in the first quarter. ... Spurs C Matt Bonner started for the second straight game. He made just 1 of 5 3-pointers in the first half as the Thunder backed off of him. ... Westbrook had four steals in the first half. ... Thunder coach Scott Brooks was issued a technical foul in the third quarter. ... Westbrook made his first 10 free throws.