But the Celtics responded with an 11-2 run, capped by a banked in three-pointer by Brown to push their lead back up to 118-99.
The Pacers are very close to the Bucks statistically in terms of both pace and threes attempted, but were four wins better thanks in part to a better defense.
Tuesday marked the ninth straight game that Antetokounmpo has scored at least 20 points against the Celtics.
The performance is even more impressive considering how little the Celtics relied on Brown during his postseason debut last season. Boston point guard Terry Rozier, meanwhile, has put up 23 points and eight assists per game while shooting 57.1 percent from the floor and drilling a game-winner in Game 1.
Celtics guard Jaylen Brown led the way with 30 points and five other Boston players scored in double figures.
Rozier has shined thus far in Kyrie Irving's absence, averaging 23 points, 5.5 rebounds and 3.5 assists in this series and he is yet to turn the ball over in 78 minutes of action.
In the first two games, the Celtics have done a good job letting the supporting cast of the Bucks beat them rather than their stars. Game 3 is Friday night in Milwaukee. While Boston is doing it with the next man up, the Bucks can't get it done with their normal rotation. They have 35 turnovers in two games, which is way too much.
The Celtics turned the ball over just five times and won on a night where the Bucks shot 60 percent from the floor. Larkin stretched the lead to 20 before the Bucks got the next six for a 103-89 game into a Stevens timeout with 5:57 to play. The Australian centre grabbed four of Boston's eight first-half offensive rebounds, and gave the Celtics multiple second-chance opportunities. It started when Jabari Parker and Khris Middleton miscommunicated, allowing Brown to get an open look from deep on the left wing, which he knocked in.
The Celtics bench came up big, outscoring their Milwaukee counterparts 41-25. And more importantly, will they be able to get this series back on track? Sooner or later, the Bucks are going to have to have someone else step up or this is going to be a short series.
"I went back and watched some film with coach". Take the points and the Celtics in this one.
Now maybe this was a response at Terry Rozier calling Eric Bledsoe, "Drew Bledsoe" and that would make sense.
"We not taking anybody lightly", he said.
"Who?" Bledsoe said, then, "I don't know who the (expletive) that is".