MIAMI — Jalen Brunson didn’t sit for a single second Wednesday night as the Knicks saved their season by beating the Heat in Game 5 of their Eastern Conference semifinal series.

They lost their season during a two-minute span without Brunson on Friday.

The Heat, thoroughly outplayed by a dominant Brunson in the first quarter, went on an 8-0 blitz as soon as the star guard finally got a breather in the second.

Miami, which had been down as many as 14 points, took the lead and went on to eliminate the Knicks with a 96-92 Game 6 victory.

It showed exactly why Knicks coach Tom Thibodeau had been terrified to rest Brunson in the absence of injured Immanuel Quickley during the Game 5 win at Madison Square Garden.

The tiniest breather for the star guard helped send the Knicks packing for the summer before a sellout crowd of 19,737 at Kaseya Center.

Even though Quickley missed a third straight game with a sprained left ankle, the Knicks were still rolling early.

They were up 31-17 after Brunson passed to power forward Julius Randle for a turnaround fadeaway with 2:40 left in the first quarter.

They appeared on the way to forcing a climactic Game 7 on Monday at the Garden.

But appearances won’t get them much.

Miami responded with a 20-5 run to not only get back into the game, but also to take the lead — and the momentum — for good.

Kyle Lowry passed to Bam Adebayo for a floater that cut the lead to 36-29 with 9:55 left in the half, and Adebayo was fouled in the act.

Brunson — who had played 92 ¹/₂ consecutive minutes without a break — finally got a reprieve. He went to the bench for the first time since 6:25 left in the first half of Game 4.

The ensuing free throw by Adebayo started a string of eight unanswered Miami points.

The Knicks sorely missed Quickley, the Sixth Man of the Year runner-up.

Adebayo’s putback dunk gave the Heat the lead at 47-36 with 7:51 left in the half.

By the time Thibodeau sent Brunson back in for Miles McBride three seconds later, the Knicks had already ceded all the momentum.

Yes, Obi Toppin briefly put them back up 44-41 midway through the second quarter, but Miami was not only back in it, but about to win it.

The Heat led by one at the half, by three after three quarters and held the Knicks at arm’s length in the fourth.

But it was that blitz in the second that did the Knicks in.