Tim Duncan scored 27 points and San Antonio took advantage of Ibaka's absence to dominate the paint, beating the Oklahoma City 122-105 on Monday night in the opener of the Western Conference finals.
Tony Parker did not appear limited by a hamstring injury, scoring 14 points and having 12 assists in 36 minutes.
"We always want to try to penetrate," Parker said. "We always want our ball movement, that's how we play — kick and pitch and stuff like that. You know, obviously it's a little bit better with (Ibaka) not being in the paint, but we're still going to try to penetrate and make stuff happen."
The Thunder got their usual offensive outputs from All-Stars Kevin Durant and Russell Westbrook, who scored 28 and 25 points respectively. But Oklahoma City's remaining starters, Nick Collison, Thabo Sefolosha and Kendrick Perkins, combined to score five points with 13 rebounds and one assist.
But it was defensively were the Thunder struggled without Ibaka, who will miss the remainder of the post-season after suffering a calf injury in Oklahoma City's series clincher against the Los Angeles Clippers.
The Spurs had 66 points in the paint and shot 58 per cent from the field. It was the highest shooting percentage allowed by the Thunder in the post-season since relocating from Seattle.
"We're a no-excuse team," Oklahoma City coach Scott Brooks said. "Serge is out. He's not coming back. We have to play better. We have to play better. If we expect to beat one of the best teams in basketball, and a very good offensive team, we have to play and we're not going to make an excuse."
The Spurs fed Duncan early with Ibaka out, and the veteran responded by shooting 6 for 7 in scoring 12 points in the opening quarter.
Parker, who suffered a Grade 1 left hamstring strain in San Antonio's series clincher against Portland, drove the paint and dished to Duncan early before looking for his own shot midway through the quarter.
"That's part of our game plan," Duncan said. "He knew that they weren't going to let him shoot the ball like he did in the last series. They were going to try to take that away from him, so he knew he was going to have to be an assist man."
Parker scored all but two of his points in the first half as the Spurs beat the Thunder for the first time this season.
Even though San Antonio improved to 7-1 at home in the playoffs, winning their past five games by an average of 20.6 points, Monday's victory was not easy.
The Spurs also still remember what happened in the 2012 conference finals, when the Thunder won four straight to rally from an 0-2 deficit.
"We knew that we have to play our best game to compete against them, and I think it's great to have an appropriate fear," Parker said. "They played great against us in 2012, and we know that we have to be perfect. They're younger than us and more athletic, and so we have to be more perfect."
San Antonio played nearly perfectly offensively and still rallied to take a 76-75 lead on Westbrook's 17-foot jumper with 5 minutes left in the third quarter.
"We don't believe in moral victories," Durant said. "Third quarter was obviously our best quarter, but we didn't close it out well. It's Game 1, we've got to make adjustments and be better for the next game. We're not taking no moral victories out of it."
Despite missing his first four shots, Westbrook continued to bull his way into the lane and it paid off as the game wore on.
Westbrook had 12 points in the third quarter, continually driving past Parker and the Spurs before they could settle in defensively.
With the exception of a pair of free throws by Derek Fisher, Westbrook and Durant scored all of Oklahoma City's points in a 23-22 third quarter.
The extended efforts exerted by the Thunder's two All-Stars eventually took a toll, especially with the Spurs bench coming to life. Westbrook and Durant were limited to seven points in the final quarter.
Durant and Westbrook were a combined 19 for 40. Durant was 1 for 4 in the fourth quarter.
"That's the key with Kevin," Popovich said. "You're obviously not going to stop him, but making him work hard is certainly the plan. It's everybody's plan, no matter who he plays against, they're going to make him work hard. I thought Kawhi was good, didn't foul, but I think the team did a nice job behind him, helping him."
NOTES: Popovich had some fun with former Spurs player Steve Kerr, who will continue as an analyst for TNT through the Western Conference finals. Kerr, who became head coach of the Golden State Warriors last week, interviewed Popovich prior to the game. "Well, I'm not really sure why I have to have him interview me before the game because he's a competitor now. That's my concern. I don't understand that one," Popovich said, smiling.