Boston guard Marcus Smart returned after missing Game 1 against Miami and had 24 points and 12 assists to lead the Celtics to a blowout win in Game 2. The series moves back to Boston for Game 3 on Saturday. Lynne Sladky/Associated Press

BOSTON — Marcus Smart brought the energy boost the Celtics needed to ignite a blowout win in Game 2 of their Eastern Conference finals matchup with the Heat.

Now armed with home-court advantage in the series, Boston will look to maintain its edge at TD Garden during Saturday’s Game 3, where it will be opposite a Miami team that is dealing with new health concerns.

A chance to lead a series is a welcome change in position for Boston, which had to play catch-up throughout its second-round series with Milwaukee before rallying to win Games 6 and 7. The Celtics are 4-0 following a loss this postseason.

Smart, the NBA Defensive Player of the Year, said his goal was to bring the edge he’s become known for in Boston.

“Being the energy that I am, being the point guard that I am I take a lot of pressure off our guys so they don’t have to force it as much,” Smart said. “So that they can be who they are.”

Sidelined with a mid-foot sprain in Game 1, Smart watched as Boston was outscored 39-14 in the third quarter on the way to a 118-107 loss. In Game 2, he contributed 24 points and 12 assists in the Celtics’ 127-102 victory.

He supported big nights from Jayson Tatum (27 points), Jaylen Brown (24 points) and Al Horford, who had 10 points in 32 minutes after sitting out the series opener while in the health and safety protocols.

“I just kept telling myself, Game 2 you’re playing,” Smart said. “I don’t care how hurt you are, you have to give it a shot.”

Boston Coach Ime Udoka said the consensus after Game 1 was that the Heat out-hustled his team. Miami’s schemes didn’t change in Game 2, but the Celtics equaled the Heat’s physicality and intensity.

“We pride ourselves on being one of the tougher teams,” Udoka said. “We knew if we matched that we’d be in good shape.”

The Celtics led 70-45 at halftime and snuffed out the Heat’s attempts at a comeback by playing them even (26-26) in the third quarter. Down 25 entering the fourth, Heat Coach Erik Spoelstra elected to rest his starters.

Heat forward P.J. Tucker left the game with a knee bruise. He had an MRI Friday before boarding the team plane to Boston.

Point guard Kyle Lowry’s status also remains up in the air after he missed Game 1 with a hamstring issue. He’s missed eight of the last 10 games and hasn’t played since Game 4 of Miami’s second-round series with Philadelphia.

Asked after Game 2 about the prospect of not having Tucker, Jimmy Butler said the Heat would adjust as necessary.

“I think he’ll be all right,” Butler said. “If he’s not ready to go, though, everybody else has to be ready to go. Those are some even bigger shoes to have to fill because he does it on the defensive end. We’re capable of it, though.”

That will be easier said than done against Celtics team that exposed Miami’s attempts to mix in some zone defense by connecting on 20 of 40 attempts from 3-point range.

Horford’s presence also made Heat center Bam Adebayo a virtual non-factor. Adebayo had nine rebounds and six points.

“The beauty about this team is we got to play through adversity early on in the season with injuries and stuff like that. COVID. We got to see what we were really made of,” Smart said. “It did feel good to have unit out there that we know when we’re out there what we can do.”