His final numbers: a career-high 44 points, 10 assists, eight rebounds.

And somehow, even a night like that wasn’t enough to beat the Miami Heat.

LeBron James scored 34 points and grabbed 10 rebounds, Dwyane Wade scored eight of his 23 points in the extra session and the Heat rallied from 15 down to beat the Celtics 115-111 on Wednesday night — taking a 2-0 lead in the Eastern Conference finals by pulling off the biggest comeback in franchise postseason history.

“There’s no turning back. It’s the conference finals,” Rondo said. “I wanted to play every minute. I thought I didn’t hurt my team by me playing every minute. I wanted to go out there and continue to do my best for my team.”

That he did, shooting 16 of 24 from the floor, 10 of 12 from the foul line and making both his 3-point tries. Boston scored 12 points in overtime and Rondo had every one, giving his team the lead on three possessions before the Heat found a way to finally escape.

“Rondo was absolutely amazing,” James said. “The performance he put on tonight will go down in the record books.”

The Heat expected Boston’s best — and the Celtics didn’t disappoint, yet still head home for Game 3 on Friday night facing a deficit no Boston team has been able to successfully overcome in a series since 1969.

“Listen, we played terrific,” Celtics coach Doc Rivers said. “I told them, we played extremely hard. I thought we played with great heart tonight, but I didn’t think we played smart all the time. And there’s things we can absolutely fix, and we’ll do that. We’ll be ready for Friday.”

Mario Chalmers scored 22 for the Heat, who took 47 free throws — 24 by James — to Boston’s 29.

“This group had resolve,” Wade said of the Celtics. “They came out and played a great game. It was physical early. They brought the game to us. That can’t happen. We used our crowd and the energy to get back into the game and we had to play better.”

Paul Pierce scored 21 points, Kevin Garnett added 18 and Ray Allen 13 for Boston.

Rondo shrugged off his night.

“We lost,” Rondo said. “Simple as that.”

Allen’s 3-pointer with 34.3 seconds left tied the game at 99-all. James missed two shots, first a layup — he got the rebound of his own miss — and then a jumper on the final possession of regulation, and to overtime they went.

“We had to do it the tough way,” Heat coach Erik Spoelstra said.

The Heat had come back to win from 14 points down in playoff games twice before, first in Game 6 of the 2006 NBA finals — their title clincher — and again last season against Philadelphia.

And this one was slipping away, more than once. James missed two free throws 21 seconds into overtime, and Miami looked in trouble, especially since Rondo was simply taking over.

When Rondo missed a layup — he thought he was fouled, and the Celtics agreed — with 1:33 left, Miami took advantage, with Udonis Haslem getting a dunk to put the Heat up 105-103. And after a turnover on the next Boston possession, Wade drove the lane, hit the deck and watched as his layup bounced on the rim and dropped through.

Garnett stood over Wade and glared, to no avail. Wade hit the free throw, and Miami was up 110-105 with 59.7 seconds left. By then, the no-call on Rondo had the Celtics seething.

“It was obvious,” Rondo said.

Added Allen: “We all thought he got hit. I’ll say it. He did, but what can you do about it?”

Miami was down by 15 in the first half and by as many as 11 in the third quarter, before a pair of 3-pointers by James started a comeback. Wade made consecutive jumpers midway through the third to shake off a slow start to his night and get the Heat within three both times, and the 2006 NBA finals MVP set up Haslem for a three-point play with 2:55 left that gave Miami its first lead since the opening minutes, 73-71.

As Haslem’s shot dropped, Wade spun at midcourt and punched the air. More highlights followed.

Miami’s lead got to as much as seven in the third after James blocked Pierce’s shot near the rim, sending the ball high into the air and starting a sequence that was capped by a three-point play from Wade, pushing the margin to 78-71. It capped a 12-0 run for the Heat, who took an 81-75 lead into the fourth.

It was the fifth straight game where Miami outscored its opponent by double-digits in the third quarter. In each of the previous four of those outings, Miami never trailed in the final period.

That streak ended in this one.

“It’s been very key for us, whether we’re up, whether we’re down, to win that quarter,” Wade said. “But in the fourth quarter, even when we were down, we felt like we were close enough. … We never felt like we were out of it.”

They weren’t out of it — but a call that Boston argued against played a big role in the Celtics getting the lead back.

James stole the ball from Rondo early in the fourth, drove down the court and got wrapped up by Mickael Pietrus, who was assessed a clear-path foul, meaning Miami got two free throws and the ball. James missed both foul shots, Mike Miller missed a 3-point attempt later in the possession, and the lead stayed at 85-81.

Barely a minute later, it was gone. Pietrus hit a 3-pointer, Rondo followed with a steal and layup and Boston led 86-85. The Celtics led by five with 3:50 left after a jumper by Pierce, and the Celtics looked to be in control.

It was temporary. The Heat scored the next nine points, Haslem’s jumper with 1:08 remaining put Miami up 98-94. So of course, back came Boston — Allen’s 3-pointer tying the game a few moments after Pierce fouled out.

“One of the best games I’ve played in, win or lose,” Heat forward Shane Battier said. “It’s easier said when you win — but it’s unbelievable.”

So was Rondo.