Kevin Garnett has a big game at home in Game 3 with 24 points on 10-of-16 shooting and 11 rebounds as Boston holds off Miami — and perhaps its inevitable breakup — for at least one more game. (Elise Amendola/Associated Press)

Face down and knuckles pressed against the parquet floor, Kevin Garnett propped himself up and went back down. Up and down, up and down, he went. And, after eight push-ups, Garnett finally got up on his feet as the raucous crowd at TD Garden erupted with applause.

A home loss on Friday to the Miami Heat would have possibly signified the beginning of the end to the five-year run for the Boston Celtics’ trio of three future Hall of Famers, Rajon Rondo and Doc Rivers.

But the Celtics summoned a 101-91 victory that proved that the old men in green had enough to get back up. Behind Garnett’s infectious energy, Paul Pierce’s timely scoring, Rondo’s all-around floor leadership and Ray Allen showing he still has some hops, the Celtics moved within 2-1 in the Eastern Conference finals.

“My goal was to win. By any means necessary,” Rondo said after scoring 21 points with a game-high 10 assists only two days after an incredible 44-point, 10-assist, eight-rebound game in a Game 2 loss. “We needed to get the win.”

Garnett scored a team-high 24 points and grabbed 11 rebounds and Pierce had 23 points for the Celtics, whose lead grew to 24 points in the fourth quarter when Allen — who has been playing, and struggling, all postseason with bone spurs in his right ankle — drove down the lane for a one-handed dunk.

The Heat made an emphatic run to cut the lead to single digits midway through the period, but the Celtics fended off the run, countering with a Garnett dunk, a Pierce jumper or Rondo layup. Game 4 is Sunday in Boston.

“Everybody knows we’ve been able to bounce back,” Pierce said. “We know we’re capable. We’re not going to lose confidence being down 2-0. You definitely don’t want to get in a situation where you go down 3-1 and they have two games left at home. It doesn’t really figure in your chances.”

The win snapped a five-game playoff winning streak for the Heat, which got little outside of a virtuoso performance from three-time league most valuable player LeBron James, who finished with a game-high 34 points but was limited to just four in the final period.

James came out determined to carry the Heat to a 3-0 series lead, scoring 16 points in the opening period and giving Miami a 28-22 lead when he drilled a 16-foot jumper with 2 minutes 34 seconds left in the first quarter. The Celtics answered by scoring the next 15 points, fueled by suffocating defense, the surprising contributions of reserves Keyon Dooling and Marquis Daniels and the fitness-crazed Garnett.

Dooling started the run with a three-pointer, Daniels made a layup and Dooling had a stunning blocked shot on James that led to a layup on the other end. Garnett then scored the next six points, sandwiching four free throws around a layup. He rose to fight for a rebound and Heat reserve big man Udonis Haslem came over the top of him, knocking him to the ground. Garnett crumpled to the ground and laid there for a few seconds before flipping over for a few push-ups as his teammates stood around him and watched.

“I want people to notice it was on the knuckles. That’s old-school,” Garnett said. “There’s very few who do them on their knuckles. That’s some Army-Navy typle stuff. Yeah, knuckles.”

The Heat couldn’t find an offensive rhythm after James’s initial scoring outburst. Miami went 8:41 without a field goal in the first half, until he hit a turnaround bank shot to bring Miami within 39-32.

For the first time in a few weeks, James didn’t have Dwyane Wade along for the ride. With all-star forward Chris Bosh missing his seventh consecutive game with a strained abdomen, Wade and James had finally appeared to discover how to work effectively off one another. They took turns dominating the opposition and had combined for 308 of the Miami’s 529 points (58.2 percent) during the string of five consecutive wins.

But after scoring at least 22 points in the past five games — and taking control in overtime of Miami’s overtime victory in Game 2 — Wade struggled from the floor as he missed 11 of his 20 field goal attempts and finished with 18 points. He lacked his usual aggressiveness and didn’t attempt any free throws after taking 17 in the first two games of the series. Mario Chalmers had 14 points and Mike Miller added 11 for the Heat.

“We’re attack guys,” James said of himself and Wade. “We’ll continue to attack and try to force the issue. That’s what we do, and that’s why we’re in this position now. It starts with us. And it trickles down to everybody else.”

Boston held the Heat to just 14 points in the second period and led 55-42 at halftime. The Celtics opened the third quarter on a 14-4 run and took a 67-46 lead when Daniels (nine points) converted a three-point play.

James tried to keep the Heat in the game, but the Celtics kept getting contributions from all over. Rondo leaped to intercept a bad pass from James, got fouled and heard chants of “MVP! MVP!” as he stepped to the foul line.

Pierce knocked down a three-pointer to give the Celtics 22-point lead at the end of the third quarter, then Allen (10 points) put them ahead, 87-63, with his dunk.

Boston couldn’t hold on to the huge lead, as Miller buried two three-pointers and Wade finally made a few shots, but the Celtics got the finishing touches from Rondo and Garnett.

“All of our energy. All of our focus right now is on Sunday,” Heat Coach Erik Spoelstra said. “We still have a golden opportunity.”