Finally forced to sit for most of the third quarter, James wasn't mad, and the Miami Heat weren't worried.
"We had the lead going into the fourth quarter on the road, and then we had the best player in the game coming in. So we were fine," Dwyane Wade said.
And James, over the final 12 minutes, was exceptional.
James scored 32 points, including eight straight to start the fourth quarter and break open the game, and the Heat took a 3-0 series lead, sending the New York Knicks to an NBA post-season-record 13th straight loss, 87-70 on Thursday night.
James had 17 points in the final period for the Heat, who held the short-handed Knicks to eight field goals in the second half and will go for the sweep Sunday afternoon.
"He just has to stay with it," Heat coach Erik Spoelstra said. "He had some turnovers, he had some mistakes but he was able to keep his head in it."
Wade added 20 points for the Heat and Mario Chalmers had 19, hitting consecutive 3-pointers in the fourth quarter when the Heat finally brought some beauty to what had been an ugly game.
"My mindset was to make plays for our team to try and help us win down the stretch," James said. "I was able to come in and make some plays to help us win."
Carmelo Anthony scored 22 points but shot 7 of 23 for the Knicks, who are playing without Amare Stoudemire, Jeremy Lin and Iman Shumpert and needed a super effort from Anthony that he didn't come close to providing.
"When you can't score the basketball, that makes the game extremely hard, no matter how much defence we go down there and play," Anthony said.
The Knicks broke the record set by Memphis from 2004-06. They haven't won a playoff game since April 29, 2001, Game 3 of a best-of-five series against Toronto.
No NBA team has overcome a 3-0 deficit.
"It's a tough one. It's an uphill battle, but it's one we have to go through," centre Tyson Chandler said. "Obviously no one wants to be in a hole 0-3, you know in the playoffs especially against a tough team like (Miami), but that's the way it is and we've got to keep fighting."
Chris Bosh had nine points and 10 rebounds hours after the birth of his first child. He flew to New York with the Heat on Wednesday, then quickly hopped on a flight back to Miami after learning his wife was in labour. He returned Thursday afternoon following the birth of his son, arriving at the arena about 30 minutes before the game.
In a sloppy game between two star-studded teams, Miami went 10 minutes without a field goal in the second half, followed by the Knicks managing just three baskets in the third quarter.
Then James, who finished with eight turnovers, took over.
He came off the bench to start the fourth after sitting most of the third in foul trouble, quickly providing the best offensive stretch in the game. He nailed a 3-pointer, followed his own miss, then hit again from behind the arc, turning the Heat's two-point lead into a 66-56 cushion with 10:36 remaining.
"He was in foul trouble," Bosh said. "He was struggling a little bit and he had pretty much the whole third quarter to think about what was going on. I think that was good for him. I think it really built a desire in him a little bit and then he made sure we got off to a great start in the fourth quarter which was very important for us."
The Heat put it away midway through the period, when Wade made a jumper before Chalmers hit twice in a row from behind the arc to make it 77-62 with 5:40 to play.
Fans started leaving, realizing there was little hope of the Knicks making up 15 points on anybody with the lineup they have.
The Knicks shot 32 per cent, getting a 5-for-18 night from JR Smith. New York shot 4 of 20 from 3-point range, with Smith missing all five.
During one hideous stretch, Baron Davis' jumper gave the Knicks a three-point lead with 8:46 left in the third, but they didn't hit again for 7 minutes — and even that make was ugly. Anthony flung in a shot off the backboard while being fouled and tied the game at 51.
"Offensively we just didn't have it," Knicks interim coach Mike Woodson said. "We were so stagnant and I got to take the heat for that."
Lin is practicing again after knee surgery but is not ready to return. Shumpert tore a knee ligament in Game 1, and Stoudemire is hoping the hand injury he sustained punching a fire extinguisher case following Game 2 is healed enough to let him play Sunday.
Desperate to see playoff success, Knicks fans were loud early, chanting "Beat the Heat! Beat the Heat!" but the Knicks gave them little to cheer about once the game started. They made one basket in the first 5 minutes and fell behind by as many as nine points, but then shut down the Heat from the field after Bosh's basket with 4:59 left and tied it at 19 by period's end.
James came in averaging 29.9 points at the current Madison Square Garden, trailing only Michael Jordan and Kobe Bryant among opponents who played here at least 10 games. Wade was just behind in fourth with 27.3 per game.
Yet the superstars both started 1 of 6 from the field, James seeming particularly frustrated with the officials and even teammates. Once a fan favourite at Madison Square Garden — Knicks fans hoped he would sign here as a free agent in 2010 — he was booed, mocked and cursed by the crowd Thursday.
He eventually would get on the roll he is accustomed to here.
The Heat won the opener by 33 points and took Game 2 104-94 on Monday, when the Knicks' biggest problems came after the game. Stoudemire punched a fire extinguisher case in the arena and badly cut his left hand, needing surgery Tuesday to repair a muscle. He sat on bench with his arm in a sling.
Steve Novak started for him but took only two shots and missed them both.
Notes: Chandler was honoured in a pregame ceremony for winning the NBA's Defensive Player of the Year award. The Knicks also held a moment of silence for former coach and scout Andrew "Fuzzy" Levane, who died earlier this week at 92.