Paul Pierce and LeBron James fouled out in overtime, but the Boston Celtics still had Rajon Rondo and the Miami Heat still had Dwyane Wade.
Rondo scored the go-ahead bucket and Wade missed a three-pointer at the buzzer Sunday night, giving the Celtics a 93-91 win and tying the Eastern Conference finals at two games apiece.
The game went to overtime only after Miami came back from an 18-point deficit in the first half, when Pierce was knocking down shots, Ray Allen was hitting three-pointers and Rondo was dissecting the defense with sharp passes. Even Keyon Dooling got in on the act.
Indeed, all was right with the Celtics until the end of third quarter when the Heat started to make a run to turn a lopsided game into a dog fight.
James hit a tying three-pointer in the final minute of regulation in front of a stunned TD Garden crowd, but also passed on the final possession to Udonis Haslem, who missed a jumper.
In the end, Boston emerged with its second straight win and will head back to Miami for Game 5 on Tuesday in a tied series instead of a 3-1 hole.
"No one said this was going to be easy," said Heat coach Erik Spoelstra. "It was a heck of a half, but is sure wasn't a heck of a game."
Pierce had 23 points, but lasted only 38 seconds past regulation before he fouled out of another game. Kevin Garnett added 17 points and 14 rebounds, Allen scored 16 and Rondo, the overtime hero in Game 2, finished with 15 points and 15 assists.
Rondo had three of Boston's four points in overtime after scoring all 12 of their points in the extra session last Wednesday. His layup with 2:33 left made it a 92-91 game and James fouled out soon after.
Rondo later made 1-of-2 free throws for a two-point edge and the Heat turned to Wade with 14 seconds left.
Wade held for the shot on the high right side, got Marquis Daniels to fly past on a pump-fake, but his shot rattled off the rim as the buzzer sounded.
"I thought it looked good honestly when it left his hands," said Celtics coach Doc Rivers, who said he warned Daniels about the pump-fake.
James had 29 points and Wade scored 20, but the Heat had just two points in OT on a Haslem dunk.
Boston went 9-for-27 on threes, but seven of the makes came in the first half.
The Heat didn't take their first lead of the game until 3:38 into the fourth quarter, capping a 15-2 run left over from the third.
James was whistled for his fourth and fifth fouls in a 15-second stretch in the fourth -- Pierce took a charge under the Miami basket on a close call, and James and Garnett got double fouls on a physical play underneath the basket.
Pierce picked up one of his six fouls on a charge, too, when he ran into Shane Battier at the end of a break with Rondo.
Still, the Celtics were in front by three after Garnett's bucket in the left post with 52.4 seconds left. James knocked down a three from up top at the other end to tie it, then worked an offensive foul out of Garnett, who had James' arm wrapped up before the Miami star was knocked over.
James, though, passed under tight defense at the other end and all Haslem could muster was an off-balance shot from the left side as time expired.
The Heat gave up more points in the first half -- 61 -- than in any other half this postseason, trailing by as many as 18 while one of their stars had a hard time getting going.
But Wade, who was just 2-for-11 in the first half for eight points, scored nine in the third quarter while missing just two of his six shots.
After Dooling gave the Celtics an 11-point lead with a three, the Heat ended the third quarter on a 7-1 burst capped by Wade's three to make it 73-68.
Earlier, Pierce scored eight of his 12 first-quarter points during a 21-6 run to open the game, capping it with a three. The Heat scored nine straight to trim their deficit to six, but Boston carried a 34-23 lead into the second.
Dooling knocked down back-to-back threes for a 45-28 advantage, capping a quick 11-2 run, and Boston's lead grew to 18 before halftime before the Heat cut it to 61-47 going into the break.
Dooling had 10 points off the bench and Brandon Bass scored 11 for the fourth- seeded Celtics...Chalmers and Haslem both scored 12 for the second-seeded Heat, who are still missing injured big man Chris Bosh.