MIAMI (AP) -- The Boston Celtics know the formula. They believe their defense, as has been the case time and again in these playoffs, will eventually wear down teams.
Hard to argue.
Jaylen Brown scored 25 points, Jayson Tatum added 22 and the Celtics are now one win from the NBA Finals. They ran away after halftime to beat the Miami Heat 93-80 on Wednesday night and take a 3-2 lead in the Eastern Conference title series.
``I think the mental stress and strain we put on some teams with our defense has worked and carried us through the playoffs at times,'' Celtics coach Ime Udoka said.
Al Horford had 16 points and Derrick White added 14 for the Celtics. Tatum finished with 12 rebounds and nine assists.
Bam Adebayo scored 18 points and grabbed 10 rebounds for the Heat, who shot 32% in the game _ after shooting 33% in Boston's 20-point win in Game 4. Gabe Vincent added 15, Jimmy Butler had 13 and Duncan Robinson scored 11 for Miami.
The Heat were 7 for 45 from 3-point range. They played without the injured Tyler Herro (groin), and several Miami players were questionable entering the day for a variety of ailments.
``We are not going to make any kind of deflection or any kind of excuse,'' Heat coach Erik Spoelstra said. ``Boston beat us tonight. And let's be clear about that. There's guys that are far from 100% on both sides.''
Game 6 is in Boston on Friday night, where a pair of trophies bearing the names of Celtics legends will be waiting. The Bob Cousy trophy goes to the East champs, the Larry Bird trophy to the East finals MVP, and the Celtics are one win from hoisting them.
``We've got an opportunity to do something with this group that's special,'' Brown said. ``Let's not take that for granted.''
This series has seen massive momentum swings -- a 44-14 Miami run in Game 1, a 60-21 Boston run in Game 2, a 46-20 Miami run to open Game 3 followed by a 57-33 Boston run in the same game, and a 26-4 spurt by the Celtics to open Game 4.
The Game 5 run was just as big.
The score over a 6 1/2-minute stretch of the second half: Celtics 24, Heat 2. The turnaround was 59-58 Boston to 83-60 Boston.
``In the first half it was tough because we weren't hitting shots and we were turning the ball over,'' Horford said. ``But the key for us was continuing to do what we do defending, and then on offense playing how we play. And eventually we were able to get it going.''
Boston outscored Miami 32-16 in the third quarter, holding the Heat to 17% shooting. The margin was only 11 at that point _ but a 14-2 spurt was how Boston opened the fourth quarter, Brown capping the flurry by making three 3-pointers in a span of 2 1/2 minutes, and the lead was out to 23.
Brown then sealed matters with a down-the-lane dunk with 5:19 left, the lead was 18 at that point and the countdown was on for Boston.
``We're still lining up,'' Adebayo said. ``We've still got to play these games. We still want to win.''
The Celtics haven't reached the NBA Finals since 2010. There have been four East finals trips since then, with two losses to Miami and two to Cleveland. There were also two chances like the one that awaits Friday -- Game 6 in 2012 against the Heat and Game 7 in 2018 against the Cavaliers -- when the Celtics had a chance to claim the conference title simply by winning a game on their home floor.
They lost both, LeBron James serving as the official thwarter both times, with 45 points to save Miami in the 2012 game and 35 to lift Cleveland in the 2018 clincher.
He won't be in the Celtics' way this time.
Miami will need somebody to provide some semblance of an impersonation.
``We know what we're capable of,'' Butler insisted.
Offense was in short supply in the first half. Miami led 19-17 after one and 42-37 at the break. Tatum was 1 for 9 at intermission, Butler 2 for 8, and the teams combined to shoot 37.8% from the field and 21.6% from 3-point range.
Miami, somehow, got colder to start the second half. The Celtics did not.
The Heat missed their first nine shots from the field after the break, not getting anything to fall until Butler fended off contact and scored on a drive that got Miami within 49-48 with 6:53 left in the third.
But soon, the Celtics had control. Of the game. And the series.
``If you want to break through and punch a ticket to the finals, you're going to have to do some ridiculously tough stuff,'' Spoelstra said.
Celtics: Boston is now 42-7 this season when holding teams to 105 points or less. ... Marcus Smart tested his sprained ankle pregame, declared himself good to go and had only five points but the Celtics outscored the Heat by 13 points in his nearly 24 minutes. ... White and Robert Williams III were a combined 7 for 8 in the first half, while the rest of their teammates were a combined 6 for 26.
Heat: Max Strus was 0 for 9, Kyle Lowry was 0 for 6, and the Heat starting guards are a combined 1 for 28 in their last two games. The 0-for-15 on Wednesday was the worst playoff showing for a starting backcourt since the NBA began tracking starters in 1970. ... It was the third-lowest point total of the season for the Heat (78 vs. Boston on Nov. 4, 79 vs. Philadelphia on May 6).
Game 6 will be the 140th playoff game for Horford. Nobody has been in more postseason contests without appearing in the NBA Finals -- something that he and the Celtics could change with one more win over Miami.
It was the 14th time in the last 19 games during these playoffs where the final margin was at least 10 points.