T.J. Warren scored 24 points to help Indiana beat the Thunder 107-100 on Wednesday night.
Oklahoma City led by a point at halftime, but the Pacers outscored the Thunder 58-50 after the break.
Domantas Sabonis added 17 points and 13 rebounds for the Pacers. They have won seven of eight.
Eight of Oklahoma City's 12 losses have been by seven or fewer points. The Thunder have battled the better teams on the schedule but have squandered halftime leads against the Los Angeles Lakers, Los Angeles Clippers and Milwaukee Bucks.
Steven Adams scored 20 points on 8-for-8 shooting and Danilo Gallinari and Dennis Schroder each added 18 points for the Thunder.
Indiana led 103-100 in the final minute of the fourth quarter and Oklahoma City had a chance to tie. Terrance Ferguson missed a 3-pointer from the corner with 17 seconds left, and Warren made two free throws at the other end with 13.2 seconds to go to put the Pacers in control for good.
The Pacers are at Detroit on Friday night.