Antetokounmpo had 20 points, eight rebounds and eight assists, and the Bucks routed the Celtics 116-91 on Wednesday night to advance to the Eastern Conference final.
After sweeping Detroit in the first round, top-seeded Milwaukee struggled in Game 1 against Boston and lost 112-90 in one of its worst offensive performances of the season. But Antetokounmpo led the way as the Bucks responded with four straight wins by a combined 65 points.
"I think our mindset changed," Antetokounmpo said. "In the first game, we weren't focused enough. We weren't ourselves. The next four games, we came out with a different approach, a different mindset."
The Bucks used a balanced attack to close out the Celtics in Game 5, placing seven players in double figures. Khris Middleton had 19 points and eight rebounds, and Eric Bledsoe finished with 18 points.
Next up for the Bucks is the winner of the Philadelphia-Toronto series. The Raptors are up 3-2 heading into Game 6 on Thursday night.
It's the first Eastern Conference final for Milwaukee since 2001.
"At the end of the day, we realize we've never been there before," Antetokounmpo said. "We're really hungry to achieve our goals. That's all we care about. As long as we play hard, we really don't care about what anybody has to say."
Prior to the clinching win, several Bucks took turns speaking to the team.
"Giannis' speech was, `A lot of us probably came from nothing and we have the opportunity to write our own story right now.' That's what everybody did," George Hill said.
The Celtics clamped down on Antetokounmpo for most of the game, but Middleton, Bledsoe, Hill and Nikola Mirotic picked up the scoring to help rob the game of any drama in the final minutes.
Hill finished with 16 points, and Mirotic had 10 points and 11 rebounds. Malcolm Brogdon also had 10 points in his return to the lineup after being sidelined by plantar fasciitis.
"Everybody was ready to play," Hill said. "Everybody was ready for the opportunity to put them away as quick as we can."
"Not what we expected," Boston center Al Horford said. "Just disappointing for us. At the end of the day, really, you have to give Milwaukee credit. They're just a better team than us. That's a reality."
Antetokounmpo picked up his third foul when Jaylen Brown drove to the hoop early in the second half, but he stayed in the game. He stole an Irving pass and slammed it home to make it 65-52 with 6:45 left in the third quarter.
Antetokounmpo, one of the front-runners for NBA MVP, closed out the period with consecutive baskets, including a finger-roll layup that gave the Bucks an 80-62 lead.
"They played like they wanted it," Irving said.
Irving went 6 for 21 from the field in what might have been his final game with Boston. He is eligible for free agency in the offseason, and his future is one of the major questions facing the Celtics this summer.
"I understand we didn't meet the outside expectations," coach Brad Stevens said. "We rode a roller coaster most of the year."
Irving's only 3-pointer of the night trimmed Milwaukee's lead to 38-32 with 2:51 left in the second quarter. But Brogdon and Mirotic each connected from long range to help the Bucks to a 52-39 advantage at the break.
Brogdon hadn't played since March 15. He also had four assists and three rebounds.
The Celtics' loss eliminated the chance for a "Boston Slam," the possibility of an unprecedented sweep of all four major pro championships in a year.
The Red Sox won the World Series in October, and the Patriots took the Super Bowl title in February. The Bruins open the Eastern Conference final on Thursday night against the Carolina Hurricanes.
Referee David Guthrie accidently sat down on a fan's lap after getting knocked backward in a collision with two players. The game was momentarily delayed while attendants cleaned up a spilled beverage.
Milwaukee gets some rest before the start of the Eastern Conference final.
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