The Boston Celtics focused on playing stingy defense against the Miami Heat to swing the Eastern Conference quarterfinal series in their favor the last time the teams met.

On Monday, look for Boston to keep the same mentality as they meet again in Miami for Game 4 of the best-of-seven series. The top-seeded Celtics carry a 2-1 series edge into the matchup against the eighth-seeded Heat.

“Everybody knows how talented we are,” Celtics forward Jayson Tatum said. “Can we be the tougher, harder-playing team?

“When you combine that with our talent level, I think it’s going to be hard to beat us. But can we start off every game essentially punching first and not reacting? That’s the test for us that we have to get up for every single game.”

The Celtics won the series opener 114-94 in Boston, led by 23 points from Tatum and 20 points from Derrick White.

The Heat evened the series at 1-1 with a 111-101 victory thanks in large part to 53.5 percent shooting from beyond the arc (23 of 43). Tyler Herro finished with 24 points and made a half-dozen 3-pointers, and Caleb Martin scored 21 points and made five 3-pointers.

Then came Game 3, when the Celtics locked down on defense and won 104-84.

Herro said he and his teammates believe that they can find their footing on offense.

“Honestly, I think the (3-point) shots are still there,” Herro said. “I have to do a better job of creating and making the right decisions when I get into the paint, the same with Bam (Adebayo), and just continue to make the right play like I’ve said this whole series.

“Guys just have to shoot the ball. They are open and we’ve just got to let it ride and let it go.”

Martin agreed. He said he would aim to be more aggressive in Game 4.

“I think there were some times when I passed up shots,” Martin said after scoring five points in 37-plus minutes in Game 3. “I felt like I was trying to get the ball moving a little bit more, being a little bit less aggressive in letting it go. So that’s on me. I can’t be as passive. I’ve got to let the ball go.”

Tatum is averaging 24.3 points, 9.7 rebounds and 6.3 assists in the series’ first three games to lead the Celtics. Jaylen Brown ranks second with 24 points to go along with eight rebounds and 2.3 assists per contest, and White is averaging 16.3 points.

Miami is led by Adebayo with 21.7 points and 8.3 rebounds per game to start the playoffs. Herro is averaging 16.7 points with 6.7 assists, and Jaime Jaquez Jr. is averaging 14 points.

The Celtics are fully healthy with no one listed on their injury report.

The Heat remain without key players Jimmy Butler (right knee), Terry Rozier (neck) and Josh Richardson (shoulder). Delon Wright, who missed Game 3 because of personal reasons, is expected to be back and available to play.

Brown said he and his teammates could not take the Heat lightly despite their injuries.

“Respecting those guys’ capability,” Brown said. “They are NBA players and they can make shots on any given night so (we are) treating them accordingly, closing out, just making them uncomfortable.”