D.J. Augustin had 17 points and David West added 13 points and nine rebounds for the Pacers, who have won five of six. George also had six rebounds and five assists.
Zach Randolph had 21 points and 15 rebounds and Marc Gasol scored 13 for the Grizzlies, who have lost three of four.
"We played, I thought, really well in the first three quarters," Randolph said. "But we have to learn how to close out a game."
Indiana played without starting point guard George Hill, who injured his right thigh against the Phoenix Suns last week.
Coming from behind or winning the close games didn't happen early in the season when they fell in a hole early with a 3-6 record.
Still without star forward Danny Granger and with the injured Hill on the bench and even without center Roy Hibbert putting up the expected numbers, Indiana remains atop the Central Division and now a game up on the Chicago Bulls.
Augustin started at point guard for Hill, a decision that came right before tip off.
"We knew with George out, it would be a challenge," George said. "But D.J. stepped up and made the game easy. Everybody had to step up and everybody did."
Augustin hit shots when they were needed most, too, including four free throws down the stretch that kept Indiana ahead.
"It felt good out there tonight," he said. "I wanted to come in and do my best to help the team win. I felt I got in a good rhythm tonight."
He hit two to put the Pacers up 84-81 with 29 seconds left and two more to make it 86-83 after Mike Conley scored a layup to get back within two.
"I just thought we got a lot more active defensively," West said. "We were much more precise in terms of our communication and what we wanted to do defensively. And guys stepped up and made shots."
George had a key steal and dunk, and West's free throws gave the Pacers the lead for good. The Grizzlies turned the ball over and West made two more foul shots to make it 74-71 with 5:37 left.
"We had it in our clutches and our first four of six posessions in the fourth quarter were turnovers," Grizzlies coach Lionel Hollins said. "We quit pushing the ball once we got the lead. It wasn't pretty."
The Grizzlies' ended a five-game winning streak over Indiana and wrap-up a two-game road trip at Boston on Wednesday.
Stephenson was listed as day to day with a left orbital contusion, but started. ... Grizzlies F Quincy Pondexter didn't travel with the team because of a left MCL sprain. ... Hibbert's first offensive rebound of the night was his 800th career. ... Indiana Fever forward Katie Douglas attended the game and was recognized for the Fever's recent WNBA championship.