PHILADELPHIA – With a spirited effort from their frontcourt, the Knicks reversed their fourth-quarter misery and defeated the Sixers 111-99 on Tuesday night.

The Knicks won overwhelmingly in the final twelve minutes as Tom Thibodeau opened his rotation and defeated Karl-Anthony Town’s old foe Joel Embiid.

OG Anunoby scored 24 points and provided the highlight, a soaring dunk early in the fourth quarter that deflated the Philly fans and energized the traveling Knicks fans.

Josh Hart closed out the night with a triple-double and an argument that rumors of the team’s demise were greatly exaggerated.

“We’re only 10 games into the season,” said Hart, who finished with 14 points, 12 rebounds and 10 assists. “We’ve had you all (in the media) crying about how we look offensively and defensively. Some people are ready to start the season, some people say we have lost our identity. We don’t listen to it. Ultimately, we know what we have and it takes some fine-tuning.”

The Knicks (5-5) got a balanced attack with their top-6 (starters plus Miles McBride) all scoring at least 14 points despite an off night from Jalen Brunson.

Even more impressive, they shot the Sixers to 37 percent and held them to under 100 points, redeeming themselves after the defensive lapse in Indy two nights earlier.

“Our defense held strong throughout the game and into the fourth quarter,” Towns said. “So it’s something to be proud of, something to hang on to and build on.”

It certainly ended on a positive note for New York, but the evening took a brief scary turn on the first possession of the second half.

Brunson stepped on defender Caleb Martin’s foot, fell near midcourt and clutched his right ankle in pain.

The point guard fled to the locker room and missed the next seven minutes of game action.

He returned and finished with 18 points on 5-of-15 shooting. Brunson was on the court when the Knicks, who had been outscored by 32 points in the fourth quarter this season, entered the final period 11-0 on Tuesday and never looked back.

“We started the fourth quarter the way we wanted and built from there,” Hart said.

By the low standards of the NBA regular season, Tuesday night had the feel of a big game.

First, it served as the NBA Cup opener and the court was overly blue to commemorate Adam Silver’s creation.

Second, it was the season debut for Embiid, who is excessively unavailable and just served a three-game suspension for pushing a reporter.

Third, it was the first meeting between the I-95 rivals since the intense playoff series the Knicks captured last season.

Both teams underwent seismic shifts over the summer, with Philly signing Paul George and Caleb Martin and the Knicks landing Towns and Mikal Bridges.

“Obviously both teams have changed quite a bit since those playoffs,” Sixers coach Nick Nurse said. “And they added two guys who can really play. Those guys are both very good players. They both have perimeter games to keep in mind. I guess we’ll have to see.

“Last year they went into the playoffs almost exclusively through Brunson. You’ll definitely get your dose of Brunson (Tuesday), but obviously you’ll be giving KAT a few shots. And they’re doing a pretty good job spreading the word. Even OG (Anunoby) gets his moments and they get through him a bit. They are much more balanced, they try to be more perimeter oriented. We have to see it.”

Nurse watched Embiid grind through 26 minutes with 13 points on 2-of-11 shooting.

He watched Towns destroy Embiid as he grabbed 13 boards with six assists and 21 points.

He saw Philly’s starting backcourt, minus the injured Tyrese Maxey, shoot a combined 2-for-11.

Nurse saw his Sixers (2-8) remaining alongside Milwaukee as the biggest disappointments in the East.

The Knicks took advantage with a stout defense, a great fourth quarter and strong performances from Towns, Anunoby and Hart.

“At the end of the day, we have (Brunson) our No. 1 option,” Hart said. “KAT has been a number one option for many years of his career. (Bridges) has been a number one option. OG can score the ball in different ways. (McBride) comes off the bench and gives us great minutes. I’m just trying to connect the dots. Great to have a game like this. I think it starts with the defense. I think we’ve surpassed them. We played Knicks basketball.”