They'll try evening the best-of-seven showdown at two games apiece when they welcome the Celtics to Bradley Center on Sunday afternoon for Game 4.
Milwaukee avoided falling into a 3-0 hole thanks to a dominant effort from its bench, which was largely a non-factor through the first two games.
Jabari Parker was the biggest surprise of that group. He'd played only 25 minutes and scored two points through the first two games, leading him to suggest he wasn't on his coach's "good side" and expressing frustration and disappointment with his lack of playing time.
Given a chance in Game 3, Parker hit 7 of 12 shots for 17 points and grabbed five rebounds while playing 30 minutes.
Thon Maker had 14 points and a career-best five blocks, and Matthew Dellavedova dished out four assists and provided the defensive pressure necessary to keep Boston point guard Terry Rozier in check.
Rozier scored 23 points in each of the first two games in the series but was held to nine Friday night. He hadn't committed a turnover in 78 minutes through the first two games but had with five in Game 3 as Milwaukee rolled to a 116-92 victory.
"They came out together as a team," Rozier said. "They punched us in the mouth early. We gotta do a better job of responding on Sunday, and we will."
Milwaukee's defensive pressure held Boston to 40 percent shooting and an 8-of-24 showing from beyond the arc. The Celtics maintained their dominance on the offensive glass, grabbing 17 boards, but after being burned in the first two games, Milwaukee limited Boston to 18 second-chance points and only gave up nine points off nine turnovers after committing 35 combined in Games 1 and 2.
"We realized how important this game was," Bucks forward Giannis Antetokounmpo said. "I think everyone brought their 'A' game, they brought their energy. Game 2, we didn't do a good job rebounding the ball or taking care of the ball. I think we did a great job of doing that (tonight). It takes effort to rebound, so I think everybody brought effort and hopefully we can carry that on to Game 4."
Antetokounmpo and Khris Middleton had almost all of Milwaukee's scoring through the first two games, and while the bench stepped up Friday with 50 points, the Bucks will also need another strong showing from Eric Bledsoe if they want to avoid going back to Boston in a 3-1 hole.
Bledsoe had been flustered by Rozier before snapping out of the funk with 17 points on 8-of-13 shooting. He missed all three of his 3-point attempts, but the Bucks still finished with a franchise postseason-record 16, and he was much more efficient with the ball, committing only one turnover.
Celtics forward Marcus Morris was fined $15,000 by the league for criticizing the officials after Friday's game. Morris scored seven points, was 2 of 8 from the field and had a team-worst minus-20.