With the Boston Celtics focused on slowing down the duo of Jalen Brunson and Kart-Anthony Towns, Josh Hart repeatedly found himself open behind the arc — and the forward repeatedly knocked down shots.

Josh Hart led all scorers with 26 points in Thursday’s 112-106 victory over the Celtics thanks to 5-of-7 shooting from downtown, including two daggers in the final 42.9 seconds to thwart Boston’s comeback attempt.

“What a shot. What a shot. The Hartbreaker comes through,” Towns said postgame. “The first one was special because he had a wide open one and turned down an open three and took a contested three and made that one. In true Josh Hart fashion. He felt good after the first one, shot the second one, made it. He’s a special player. He does so much for our team that doesn’t show on the sheet but at any moment he can do those things and we trust him with the ball.”

A few of the treys were made with the Celtics way too slow to close out on the perimeter, which seemed like a questionable strategy for a player entering the matchup shooting a career 40.6% from deep.

The Celtics, though, were without Jaylen Brown (left achilles tendinitis), the team’s two-way star known for lockdown defense. Joe Mazzulla did deploy Jayson Tatum, Derrick White, Sam Hauser and Jordan Walsh — all players familiar with this Knicks roster and capable of defending the perimeter.

But Hart was left open too many times, and it cost them in the end.

“Nah, I mean it all depends,” Hart said when asked if he’s baffled by the soft defensive coverage. “For me I always talk about I’m the fifth option, sixth option. My thought process always is how can I get these guys easy shots, get these guys involved, get them feeling good. Am I surprised with that? Nah, because I don’t go out there like, you know what I’m going to shoot seven, eight threes. That’s not really my cup of tea. But when I’m open I know I’ve got to shoot those shots. But they’re probably looking like he might shoot three or four, so let him have that.”

Fifteen of Hart’s game-high 26 points came in the fourth quarter alone. Hart said he was able to “regroup” in the second half after letting a “couple of bad plays” earlier in the game “linger a little bit.”

He came through when it mattered most, though.

Thursday’s fourth-quarter point total eclipsed his points scored in the Knicks’ past three games combined (14).

And after Thursday’s standout performance, the key Knicks starter said the obvious while playing in his best season shooting to date.

“Yeah, I think so. I’m a better shooter, more confident shooter.”