The win, coupled with Cleveland's loss at Miami, allowed the Pacers (44-31) to move within a half-game of the Cavaliers (44-30) atop the Central Division.
Golden State, meanwhile, fell for the second straight game with Stephen Curry, Klay Thompson, Kevin Durant and Draymond Green out of action.
The Warriors' sixth loss in March -- they hadn't lost more than four games in any previous month of the Steve Kerr coaching era -- came after Kerr announced before the game that one of his missing four All-Stars, Durant, is expected to return from a six-game absence for Thursday's finale of a four-game homestand against Milwaukee.
The Pacers took advantage of the Warriors' shorthanded situation in the second half, harassing Golden State into 14-for-39 shooting (35.9 percent) while outscoring the hosts 53-33 to reverse a nine-point halftime deficit.
Victor Oladipo had a game-high 24 points for the Pacers, who had clinched a playoff spot with Sunday's win over Miami.
Oladipo also found time for six rebounds and a team-high six assists in the Pacers' opener of an eight-day, four-game trip.
Thaddeus Young recorded a 17-point, 10-rebound double-double, and Bojan Bogdanovic added 17 points for Indiana, which had dropped its previous four games to Golden State by an average of 23.3 points.
The Pacers shot 48.1 percent for the game.
Nick Young had a team-high 12 points, while Quinn Cook and Andre Iguodala added 11 apiece for the Warriors, who remained one win or one Portland loss from clinching no worse than the second seed in the Western Conference playoffs.
Kevon Looney grabbed a game-high 11 rebounds for Golden State, who fell to 28-10 at home this year after having gone 114-9 in Oakland the past three seasons.
The Warriors led for the first 27 minutes until they were finally caught at 50-all when Oladipo capped a 10-0 Pacers run with a steal and dunk.
The Golden State lead was as many as 10 points in the first quarter and 15 in the second, before the Pacers scored the final two hoops of the half to get within 48-39 and set the stage for a third-quarter comeback.
--Field Level Media
Indiana | Golden State | |
Victor Oladipo 24 | Scoring | Nick Young 12 |
Victor Oladipo 6 | Assists | Quinn Cook 7 |
Thaddeus Young 10 | Rebounds | Kevon Looney 11 |
Victor Oladipo 4 | Free Throws Made | David West 2 |
Victor Oladipo 3 | Steals | Kevon Looney 2 |
Myles Turner 2 | Blocks | Jordan Bell 4 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Indiana | 92 | 48.1 | 6-21 | 8-12 | 22 | 38 | 2 | 10 | 12 |
Golden State | 81 | 40.7 | 5-17 | 6-9 | 21 | 51 | 9 | 4 | 17 |