The Spurs lead the best-of-seven series 2-1 but the Thunder at least breathed some new life into their season, which was in danger of ending with a whimper.
Power forward Ibaka, who missed the first two games with a left calf strain, scored 15 points on 6-of-7 shooting from the floor in nearly 30 minutes of action. He also grabbed seven rebounds and played strong defense, blocking four shots.
"I tried to give my team mates some energy in defense and offense," the 24-year-old from the Republic of the Congo told TNT TV.
"I think I did pretty well. Also, my team mates too, we did a great job to make them take some tough shots."
Coach Scott Brooks praised Ibaka: "Serge gave us a big lift, not only on the defensive end but the offensive end," Brooks told reporters.
"We obviously missed him the last two games but that's part of sport. You have to deal with the injuries. We bounced back tonight."
The Thunder, who lost the first two games of the series by a combined 52 points in San Antonio, looked like a different team as they played with energy and more than a touch of skill in front of a raucous home crowd.
Oklahoma City started the final quarter with a decisive 7-0 run to take a 14-point lead and the Thunder were never in danger from that point as San Antonio coach Gregg Popovich rested most of his starters over the final few minutes.
Guard Manu Ginobili led the Spurs with 23 points, including 6-of-9 from behind the arc, but scored only three in the second half.
Popovich complimented Ibaka while also expressing disgust with his own team's performance.
"Serge is always great in the paint. He blocks shots, he changes shots, he did a great job," Popovich told reporters.
"I thought our defense was pretty poor. I thought our first half was probably the poorest defense we've played in a very long time.
"It was a miracle it was a one-point game with 40 seconds to go in the first half. The only thing that kept us in the game was those threes (by Ginobili)."
The Thunder out-shot the Spurs from the floor, 46 percent to 40 percent, and also dominated the boards 52-36 in rebounds.
Oklahoma City stars Russell Westbrook (26 points) and Kevin Durant (25 points) were not at their most brilliant but still top-scored.
Guard Tony Parker had a poor game for the Spurs, scoring only nine points on 4-of-13 shooting from the floor.
Game Four is in Oklahoma City on Tuesday.
- Sports & Recreation