Golden State got a big boost from its reserves, with Jack and Landry leading the way.
Swept by the Pacers in 2011, the Warriors pulled away in the second quarter following a 12-2 run. Landry had six points during the surge on back-to-back three-point plays, and Draymond Green's tip-in gave Golden State a 32-23 lead.
Indiana's defense prevented it from getting out of hand.
The Pacers held the Warriors to one basket over 6½ minutes, forced 11 first-half turnovers and used a 17-6 run to move in front. Roy Hibbert scored on a dunk, jump hook and two free throws, while Hill had a 19-foot jumper that made it 42-41.
Curry helped Golden State to a strong finish to the half, and the Warriors got a lift from Thompson and two rookies early in the third. Thompson made a pair of 3s, Harrison Barnes followed with long jumper and Festus Ezeli later scored on a dunk to extend the Warriors' lead to 67-54.
Indiana closed to 77-72 in the third before Jack responded with a driving layup and his buzzer-beating 3 from beyond midcourt. Jack, who scored Golden State's final eight points of the period, crouched low and posed on the Warriors logo and slapped hands with Green as the Oracle Arena crowd roared.
"It was honestly just a heave," Jack said. "I thought it was going to go in off the backboard. I think I've been due for one all year. A couple of them have rimmed in and out."
Hibbert had 15 points and seven rebounds for Indiana, while Mahinmi finished with 10 points.
NOTES: This was the first of nine consecutive games against Eastern Conference teams for Golden State. ... The Warriors recalled G/F Kent Bazemore from the NBA Developmental League before the game.