Of course it was the Villanova connection that iced the game, Josh Hart to Jalen Brunson.

Of course.

They’ve been such a big part of this run together, a run that has taken the Knicks to within one win of the second round of the NBA playoffs for the first time in a decade.

Hart, the trade-deadline acquisition who has worked out so much better than anyone could have envisioned, got to the offensive rebound. He found Brunson, who sank the back-breaking 3-pointer, sending the already loud and sold-out Garden to another decibel level.

It gave the Knicks a 10-point lead with 1:45 left, and they would soon be celebrating a hard-fought, 102-93 victory over the favored Cavaliers at MSG, pushing their series lead to 3-1.

Knickanova — the nickname given to Brunson and Hart by Post columnist Mike Vaccaro — delivered.

“It’s like fairytale stuff, being with him,” Brunson said. “To see where he is now, and be on the same team again, it’s pretty awesome.”

Brunson was the hero, again the best player on the floor, producing 29 points, six rebounds and six assists. Hart, in his first start as a Knick in place of the injured Quentin Grimes, was fantastic at both ends, accounting for 19 points, seven rebounds and suffocating defense on New Yorker Donovan Mitchell (11 points on 5-for-18 shooting, six turnovers). The Knicks are now 20-9 since trading for Hart.

“It’s just one tough play after the next,” Tom Thibodeau said. “Big shot, big offensive rebounds, great defense. He’s just a winner.”

With Julius Randle struggling and sitting the entire fourth quarter, Brunson and Hart willed the Knicks to the win, along with RJ Barrett, who produced the best playoff game of his young career — 26 points and zero turnovers in 38 high-level minutes.

Thibodeau, continuing to shed that rigid narrative about himself, went with a different closing five: Hart, Brunson, Barrett, Isaiah Hartenstein and Obi Toppin.

The group put together a 15-6, fourth-quarter run that gave the Knicks command. Barrett, stepping up to the moment, scored the first five points of the spurt and Hart capped it with a driving layup over Jarrett Allen, pushing the lead to nine with 5:21 remaining.

“Every time they threw a punch, we threw something back,” Barrett said.

They can close out the series Wednesday in Cleveland, and return to the Eastern Conference semifinals for the first time since 2013, when the Carmelo Anthony-led team lost to the Pacers in six games.

For a team that was projected to finish the season under .500, reaching the second round would be a significant achievement.

Not that they are looking ahead.

“It’s not over. Not even close to being over,” an adamant Brunson said. “There’s nothing to celebrate, there’s nothing to be truly happy about. Obviously, we won [today], we’re one step closer, but we got to continue to have the same mindset and mentality that we have had the past couple of games.”

Game 4 was emblematic of this series.

The Cavaliers had their moments, particularly the 18-7, Darius Garland-led run to start the third quarter.

But the Knicks were the better team. They had the answers in crunch time.

Their star guard (Brunson) was better than the Cavaliers’ star guard (Mitchell).

Their defense was stingier, holding the Cavaliers under 100 points for the third time in this series and third in four games this season at the Garden.

Hartenstein and Mitchell Robinson were a big part of that, combining for 19 rebounds and four blocks in getting the better of Allen and Evan Mobley, keying the Knicks’ 14-rebound margin in the battle on the glass.

“I feel we’re playing extremely hard, making hustle plays,” Barrett said. “The whole team, all the hustle plays we’re making, we’re really together collectively.”

Nobody is more together than Brunson and Hart, who have known each other for nearly a decade. They’ve brought that fundamentally sound, winning-is-all-that-matters mentality they learned under Jay Wright at Villanova to the Knicks.

The two like to poke fun at each other. Hart joked that Brunson’s two offensive rebounds were a career-high.

When told at the end of their press conference Brunson actually had four offensive rebounds in a game this season, he reminded the media that in their last game as starters together — a loss in the second round of the 2017 NCAA Tournament to Wisconsin — Hart was stripped in the final seconds and Villanova down two.

Both laughed. There has been plenty to smile about since the Villanova stars were reunited with the Knicks. Sunday afternoon presented the latest memorable moment for this difference-making duo.