Westbrook finished with 20 points, 11 rebounds and 10 assists for the 11th triple double of his career.
Serge Ibaka tallied 23 points with 10 rebounds and three blocks, while Enes Kanter added 15 points with five rebounds in the win.
“We know teams are going to make runs. We did a great job of sticking together,” said Westbrook.
C.J. Miles scored 15 of his 21 in the third quarter and George Hill chipped in with 13 points and eight assists for the Pacers, which had a three-game win streak clipped.
Ibaka nailed a three-pointer late in the first quarter to cap a 7-0 surge for a 13-point Thunder lead. Oklahoma City lead 30-20 after the first quarter.
Indiana trailed by as many as 15 points in the second, but the Pacers went on an 11-2 burst to cut the deficit to six. Miles’ jumper just before the half pulled the Pacers within 48-42 at halftime.
Oklahoma City maintained its edge in the third, but Indiana kept it close until the final minutes.
Westbrook drove for a layup with 3:20 remaining to spark a 12-4 quarter-ending run that stretched Oklahoma City’s lead to 80-69 entering the fourth.
The Thunder continued to play aggressively at the beginning of the fourth, as D.J. Augustin connected with a thee-pointer prior to Anthony Morrow and Dion Waiters hitting deep shots to extend the lead to 20. – Agence France-Presse