MIAMI — When the clock struck winning time, the Knicks were again in the safe and reliable hands of their point guard.

Riding — who else? — Jalen Brunson, New York overcame a nasty first half to complete its biggest comeback of the season in Sunday’s 116-112 overtime thriller over the Heat.

Brunson scored 16 of his 31 points in the fourth quarter and OT, further cementing his Captain Clutch name while calmly dissecting Erik Spoelstra’s defense down the stretch.

It pushed the Knicks (40-20), winners of three straight overall, to 5-0 in overtime games.

“The thing that’s unique about Jalen is his poise under pressure and he can beat you a lot of different ways,” coach Tom Thibodeau said. “He can beat you with a shot, he can beat you off the dribble, he can beat you with a finish, he can beat you with a pass. He also understands who is going well. And are they sending two at him? Are they sending three at him? Are they collapsing? What’s the right play? And he’s great at it.”

Brunson was the hero again, but got plenty of help Sunday to erase a 19-point second-quarter deficit.

OG Anunoby, in particular, was a two-way powerhouse while dropping 23 points with nine rebounds and five assists.

His putback with about a minute remaining in regulation cut the Knicks’ deficit to two and represented the biggest play of the evening.

Anunoby, who has put together consecutive strong performances, then dunked the dagger with 17 seconds remaining in OT.

“Phenomenal,” Thibodeau said. “Just timely rebounds. In traffic. Assists. He did it all. Tremendous game from him.”

Josh Hart was also in the mix in crunch time, recovering from a nasty spill on the court in the fourth quarter to collect a big bucket and steal.

He said the fall on his back and head was painful, but he never asked for a sub.

“It was obviously a hard fall,” Hart said. “Then, I didn’t want to be soft, so I got up and kept playing and continued to be aggressive. It’s going to be sore [Monday], but hey man, I had a game to play.”

The requirement of so many Knicks heroics — which occurred with the struggling Mikal Bridges benched for all but a few possessions of the fourth quarter and OT — was because they were pitiful in the beginning.

New York played the first half like they enjoyed too much of their Saturday night off in South Beach, succumbing to lazy defense and allowing the Heat to drive at will.

Brunson and Karl-Anthony Towns were targeted in pick-and-roll actions — time and time and time and time again — as the Heat dropped a staggering 40 points in the paint in the first half, repeatedly hunting the Knicks’ weakest defenders and succeeding.

The tipping point was a 16-0 Miami run in the second quarter, boosting the home team to that 19-point advantage.

But the Knicks recovered in the third quarter by subbing out Towns for Mitchell Robinson, who ignited a rally and awakened the pro-Knicks crowd with a steal, an offensive rebound and a putback to cut the deficit to 3.

That set up the thrilling finish and the latest display of calm dominance from Brunson, who is becoming a lock for Clutch Player of the Year.

About half of his game-high points Sunday were in the final 10 minutes.

“He keeps opposing coaches up at night, that’s for sure,” Spoesltra said. “He’s a tough guy to game plan against because he’s so clever.

“And he’s relentless. And he’s not going to stop. If you happen to get a stop on him on any given possession, it’s not like the next possession he’s going to ease up at all. He has great stamina to do what he does. He’s second in the league in drives, second in the league in fouls drawn. You have to be pretty persistent to do that, especially for a player with his size.”