Malcolm Brogdon scored 26 points, T.J. Warren added 23 and the Pacers rallied to beat the Spurs 116-111 on Monday night after blowing a 15-point lead.
The Pacers won their fourth straight, moving into a fifth-place tie with the Philadelphia 76ers in the Eastern Conference.
Patty Mills scored 24 points to lead San Antonio and Trey Lyles added 20. The Spurs, who have lost eight of 11, dropped four games behind the Memphis Grizzlies for eighth place in the West.
San Antonio trailed 84-69 with 4 1/2 minutes left in the third quarter before rallying. The Spurs went ahead 102-98 with 6:44 remaining in the game, fueled by a pair of 3-pointers each from Mills and Lonnie Walker IV and an emphatic slam by Walker.
Walker finished with 10 points.
The Pacers regained control by pounding the paint against the undersized Spurs, who were without injured big men LaMarcus Aldridge and Jakob Poeltl.
Domantas Sabonis had nine of his 14 points in the final quarter.
Indiana was without Victor Oladipo, who suffered swelling in his right knee following the team's morning shootaround.
Doug McDermott had 14 points, going 4 of 5 on 3s.
The Pacers play at Milwaukee on Wednesday night.