MIAMI -- After perhaps the most surprising result of the postseason thus far -- the shorthanded, No. 8-seeded Heat beating the No. 1-seeded Celtics in Game 2 to tie their first-round series -- it was natural to wonder how things would play out in the pivotal Game 3.

Would Boston, after the head-scratching loss, rebound and again resemble the club that won the East by 14 games in the regular season? Or had coach Erik Spoelstra and his scrappy group found a formula it could repeat to play spoiler in the series for a second straight postseason?

The answer, emphatically, was the former.

After surrendering 23 3-pointers in their Game 2 loss, the Celtics were far more active and physical defensively Saturday night and smothered the Heat in a 104-84 Game 3 win to take a 2-1 series edge.

Game 4 is Monday in Miami.

Boston stars Jayson Tatum and Jaylen Brown said coach Joe Mazzulla challenged them to play with more defensive intensity after watching Miami go off from deep in Game 2.

"Everybody knows how talented we are. But can we be the tougher, harder-playing team?" said Tatum, who finished with 22 points, 11 rebounds and 6 assists. "If we can combine that with the talent, it's going to be hard to beat us.

"Can we start off every game, essentially, punching first instead of reacting? That's a test we have to be up for every single night."

The Celtics' response to Mazzulla's challenge was instant. Guard Jrue Holiday and his teammates locked in early against the Heat's offense, surrendering just three points through the first 6 minutes, 46 seconds of play. Boston gave up just 12 points on 5-for-21 shooting in the first quarter, which Mazzulla called "a physical, tough ... rock fight."

Boston was happy to create those kinds of conditions defensively by pushing up further on that side of the ball. Brown, who finished with a game-high 23 points, said the Celtics came in with a handful of rules after Miami's record-setting showing in Game 2.

"No 'dare' shots. Respect those guys' capability. They're NBA players, and they can get hot on any given night," Brown said. "We just wanted to make it uncomfortable for them."

The result: Miami finished 9-of-28 from 3-point range, a night-and-day difference from the 23-of-43 performance three days earlier. Heat playmaker Tyler Herro -- who had one of the finest games of his career in Game 2, with 24 points and 14 assists -- looked bothered all night, shooting just 5-of-16 for 15 points and four turnovers. He shot 0-for-5 on contested looks, according to ESPN Stats & Information data.

The Heat's 84 points were their fewest in a game all season (including playoffs).

"They were the more physical team. They bodied us [and] bullied us," Spoelstra said, adding that Boston's physicality repeatedly took the Heat out of their offensive actions and sets.

Boston turned its amplified defense into offense repeatedly Saturday, scoring 24 points off Miami's turnovers. The Heat, by contrast, scored just four points off the Celtics' miscues.

If the Celtics continue to put their foot on the pedal the way they did in Game 3, Miami -- which knocked out Boston as the underdog in last year's conference finals -- could find it difficult to mount a challenge this time. Star wing Jimmy Butler remains out with an MCL sprain while guard Terry Rozier is sidelined with neck spasms. It leaves the Heat, who already struggled to score at times, with less offensive creation against one of the league's best defending units.

"We have enough to get the job done," Spoelstra said. "We know we have to play hard, and we also have to play well."