Jayson Tatum wouldn't let it happen again.

With the defending champion Milwaukee Bucks attempting to complete a fourth-quarter comeback for the second straight game and close out their Eastern Conference semifinal, Tatum made sure the Boston Celtics instead kept their season alive and forced a decisive seventh game.

Tatum scored 46 points and the Celtics withstood a brilliant performance from Milwaukee's Giannis Antetokounmpo to win 108-95 on Friday night, the third straight victory for a road team in this thrilling series.

"I wasn't going to leave anything out there and have any regrets," Tatum said. "Just trying to do what it took."

After the Bucks reduced a 14-point deficit to four with just under 9 minutes left, Tatum took over the game. He scored 16 of Boston's 26 fourth-quarter points.

"He was unbelievable," said Antetokounmpo, who was pretty extraordinary in his own right with 44 points, 20 rebounds and six assists.

Tatum's effort set up a winner-take-all matchup Sunday in Boston. The victor heads to Miami to begin an East finals matchup with the top-seeded Heat on Tuesday.

"I don't think anybody's won two games in a row in this series," Bucks coach Mike Budenholzer said. "Now, it's the finality. You've got to go and find a way to get that fourth win and win the series. I think everybody in sport looks for that game. That college feel. That NCAA feel, where if you lose your season's done, if you win, you keep going. It's exciting."

The Bucks had won all eight of their potential series clinchers in Budenholzer's four-year tenure before Friday. This marked the first time the Bucks had lost a possible clincher since a Game 7 defeat at Boston in a 2018 first-round series.

Boston showed its grit by bouncing back two nights after blowing a 14-point, fourth-quarter lead in a 110-107 Game 5 home loss. The Bucks tried to rally again after trailing by 14 in the final period, but this time the Celtics stayed in front.

"Tonight will be the first night since that game that I'll get some sleep," said Marcus Smart, who had 21 points, seven assists and no turnovers.

Jaylen Brown added 22 points for the Celtics, who capitalized on their superiority from 3-point range. The Celtics were 17 of 43 and the Bucks 7 of 27 from beyond the arc.

Antetokounmpo tried to lead the Bucks to a second straight improbable comeback.

Boston led 84-70 in the opening minute of the fourth quarter and was up 84-73 when officials ruled Grant Williams had drawn a charge for Antetokounmpo's fifth foul. But the Bucks challenged the call and it was overturned on replay, instead sending Antetokounmpo to the line with four fouls.

Antetokounmpo made both free throws to start an 8-0 run that got the Bucks back into the game. The Bucks trimmed the margin to 85-81 on Antetokounmpo's 3-pointer with 8:42 left.

Tatum said he was thinking about that Game 5 collapse as the Bucks started to rally. He wanted to make sure the Bucks didn't win the 50-50 balls and dominate the glass the way they did down the stretch on Wednesday.

"They were tougher than us in that fourth quarter of Game 5," Tatum said. "That was in the back of my mind. That was in the back of everybody's mind, that we couldn't get beat on those kind of plays. Our season was on the line."

Tatum wouldn't let the Bucks get any closer.

After that 8-0 Bucks spurt, Tatum scored the Celtics' next 11 points. That included a fadeaway jumper as the shot clock expired to get the lead back to six plus a couple of 3-pointers.

"He went into another mode right there," Smart said. "We'd seen it in his eyes."

Tatum and Brown each hit a 3-pointer during an 8-0 spurt that closed with Smart's jumper that made it 100-87 with 4:20 remaining.

Boston maintained a double-digit edge the rest of the way.

"We had the right resolve," Celtics coach Ime Udoka said. "We talked about it after that game. We let an opportunity slip away (Wednesday) but we still had a chance to make it a better story, I guess."

MISSING PLAYERS

The Celtics played without forward/center Robert Williams for a third straight game. Udoka said Williams suffered a bone bruise in his left knee while colliding with Antetokounmpo in Game 3.

Milwaukee was missing three-time All-Star forward Khris Middleton for a ninth consecutive game. Middleton sprained the medial collateral ligament in his left knee during Game 2 of the Bucks' first-round series with the Chicago Bulls.

GAME 7 HISTORY

The Celtics own a 24-9 Game 7 record, while the Bucks are just 3-8.

But the Bucks can lean on some recent successful history in winner-take-all games. Their title run last year included a Game 7 overtime victory at Brooklyn in the East semifinals.

TIP-INS

Celtics: Tatum has scored at least 30 points in three straight games. ... After going a combined 5 of 27 on 3-point attempts in Games 3-5, Tatum was 7 of 15 on Friday. ... The Celtics were 10 of 17 from 3-point range in the game's first 14 1/2 minutes.

Bucks: Antetokounmpo, Jrue Holiday (17) and Pat Connaughton (14) combined for 75 of the Bucks' 95 points. The other Bucks shot a combined 9 of 33 overall and 0 of 13 from 3-point range. ... Antetokounmpo was 14 of 15 on free-throw attempts. ... A moment of silence was held before the game to honor Hall of Famer Bob Lanier, who died Tuesday at the age of 73. Lanier played for the Bucks from 1980-84, and his No. 16 jersey hangs from the Fiserv Forum rafters.

CREW CHIEF CHANGE

Scott Foster, the scheduled crew chief for Game 6, couldn't officiate because of an illness unrelated to COVID-19. Eric Lewis took over as crew chief with Ben Taylor working as the referee and Tre Maddox as the umpire.

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