OKLAHOMA CITY -- San Antonio fought off Father Time, the league MVP and an injury to its best player to return to the NBA Finals.

The Spurs beat the Oklahoma City Thunder 112-107 in overtime Saturday night in Game 6 of the Western Conference finals to set up a rematch with the Miami Heat.

San Antonio will host Game 1 on Thursday night and will try to avenge last year's heartbreaking loss. San Antonio led Miami 3-2 before losing Game 6 in overtime, then dropping Game 7.

"People keep talking like we weren't close to winning, but we were ready to win last year," Spurs center Tim Duncan said. "We're happy it's the Heat again. We've got that bad taste in our mouths still."

A trio of 30-somethings led the way for the Spurs. Duncan had 19 points and 15 rebounds, Boris Diaw scored 26 points and Manu Ginobili chipped in 15 points and six rebounds for the Spurs.

San Antonio pulled this one out despite All-Star point guard Tony Parker missing the entire second half and overtime with left ankle soreness. Popovich said Parker had been struggling with the ankle since Game 4 of the series. The Spurs overcame it the way they have for more than a decade -- with teamwork, passing and great performances by role players.

"We didn't know how much Tony was hurt in his ankle," Diaw said. "But we didn't want to go to Game 7, and we didn't know if he would be ready to play if we did or if he would be 100 percent, so we tried to get it over with tonight."

It was the third-best playoff scoring effort of Diaw's 11-year career and his best since 2006.

"Boris was amazing," Duncan said. "He had an unbelievable game. He's had a great series."

Russell Westbrook had 34 points, eight assists, seven rebounds and six steals, and MVP Kevin Durant added 31 points and 14 rebounds for the Thunder. But Oklahoma City committed 20 turnovers that led to 33 points for the Spurs. Westbrook and Durant each had seven turnovers.

"We started settling for too many jump shots," Thunder coach Scott Brooks said. "It just seemed like we couldn't get enough good looks at the basket. Defensively, they just had us scrambling around."

In what might have been his final game, Derek Fisher, 39, played every minute of the fourth quarter and overtime. He told Yahoo! Sports after the game that he doesn't plan to take too long to decide on retirement.

"Obviously, there are a number of people that are going to be impacted by the decision I do make whether I continue to play or [if] I decide to do something else within the game," Fisher, who is a candidate for the New York Knicks' coaching vacancy, told Yahoo! Sports. "Whatever it is, there is a lot at stake. I'm not going to rush. I'm not going to be emotional.