A struggling Jimmy Butler strung together three poor outings at a very bad time but made up for his struggles in a big way on Friday night.

The ultracompetitive forward shook off all the misfired shots and the aches in his right knee while singlehandedly carrying the Miami Heat to a 111-103 victory over the host Boston Celtics on Friday night to tie the Eastern Conference finals at three games apiece.

Butler set a personal playoff high with 47 points and also contributed nine rebounds, eight assists and four steals in a stellar all-around performance.

"My teammates and my coaches let me know to be aggressive and go out there and be the best player on the floor," Butler said. "I just have to remember that every time I take the floor."

Butler had scored a total of 27 points over the previous three games before erupting during a must-win situation in Game 6.

He made 16 of 29 field-goal attempts -- including 4 of 8 from 3-point range -- and sank all 11 free-throw attempts while reaching the 40-point mark for the second time in this series and the fourth time this postseason.

The inflammation in Butler's right knee caused him to miss the second half of Game 3. Shooting 10 of 40 from the field in a three-game span hurt just as much.

"I let my team down a couple of games," Butler said. "I wasn't going to do it again. We know what we're capable of."

Butler's knee is feeling better now and his mental game got a boost when former Miami Heat star Dwyane Wade -- a teammate of Butler on the Chicago Bulls during the 2016-17 season -- sent him a text message prior to Friday's game and told him to "go out there and continue to build your legacy."

Miami's Kyle Lowry recorded 18 points and 10 assists before fouling out for the Heat. Max Strus scored 13 points, and P.J. Tucker added 11.

Jayson Tatum registered 30 points and nine rebounds, Derrick White scored 22 points and Jaylen Brown added 20 for Boston. Marcus Smart had 14 points while Robert Williams III tallied 12 for the Celtics.

Game 7 is Sunday night in Miami.

There were a lot of prognosticators saying there would be no Game 7 after the Heat averaged just 81 points in back-to-back setbacks the past two contests.

Miami center Bam Adebayo shook his head at the rhetoric.

"Everybody thought the series was already over," Adebayo said. "That was the only motivation we needed."

It was a disappointing night for Boston, which has failed to reach the NBA Finals in its past four trips to the Eastern Conference finals.

Now the Celtics need to go on the road and win to reach the Finals for the first time since 2010.

"Our backs are on the wall," Brown said. "Game 7, loser goes home. So we have to find a way to win."

Butler converted a tiebreaking three-point play to give Miami a 102-99 lead with 2:06 remaining. Tucker made three of four free throws during a 20-second span to make it a six-point margin with 1:25 left.

Butler's jumper with 43.9 seconds left provided another six-point lead, and the Heat closed it out.

"They made timely threes late in the shot clock," Celtics coach Ime Udoka said. "We didn't contest and get out on shooters as well as we should have. We had our chances. Butler was aggressive, and we didn't match his intensity."

Miami guard Tyler Herro (groin) missed his third straight game. Herro won the NBA's Sixth Man of the Year award this season.

The Heat shot 46.2 percent from the field, including 15 of 35 from 3-point range. Miami was 24 of 25 from the free-throw line.

Boston hit 44.4 percent of its shots and was 11 of 33 from behind the arc. The Celtics were 28 of 31 from the line.

Butler had 21 points, nine rebounds and six assists as Miami led 48-46 at halftime. Tatum and Brown scored 18 first-half points apiece for the Celtics.

--Field Level Media