On the way to a 15-0 run to open the third quarter in Philadelphia on Wednesday, new Knicks starting center Taj Gibson became an offensive beast.

Known more as a defensive specialist, Gibson scored on three straight possessions — an 18-footer, a spinning, driving dunk past Joel Embiid and banging in a 3-pointer.

The 34-year-old Gibson has solidified the starting lineup by doing whatever is needed. His effect, however, on young center Mitchell Robinson may be more important when assessing his worth.

The Knicks are 3-4 since Gibson got the starting nod — 1-7 beforehand.

“He does give that starting lineup a sense of stability,’’ Knicks coach David Fizdale said. “He’s also been fantastic for Mitch. That relationship has been worthwhile.’’

After the Brooklynite signed a one-year, $10 million deal this summer, Gibson told The Post his main goal would be as a Mitchell mentor. He has lived up to every part of the agreement.

“I’m doing what the team needs and it’s needed now [starting], but it’s Mitch’s seat,’’ Gibson told The Post in Philly. “I’m just keeping it warm for him. I work out with him every day. Just trying to get him better every day. I’m doing what the team needs and being the veteran.”

At 6-foot-9, Gibson is a natural power forward, but saw spot duty at center in Chicago and Minnesota — both under Tom Thibodeau, his biggest fan.

“It’s a new game now,’’ Gibson said. “You got to be able to move your feet and guard multiple positions. I’m doing what the team needs me to do. It’s a new day and age.”

Gibson and Robinson, the Knicks’ 2018 second-round pick, have become Frick and Frack.

“I work out with him every day,’’ Gibson said. “Me and him go on the court and work out together, shoot foul shots together. I’m just trying to get him better.

“He works hard. He listens to me and understands what he needs to work on. Every day we challenge each other. I try to make him understand the game and learn. Because right now he’s just so talented, he’s just playing off pure talent.”

Robinson has been productive — if foul-prone — when healthy. He’s missed four games with assorted injuries (two sprained ankles, two damaged fingers, a concussion).

Having Gibson teach him the nuances should help the shot-blocking/alley-ooping Robinson take another step this season after a Second Team All-Rookie campaign in 2018-19. Robinson has grown as an alley-oop specialist in recent games, with Marcus Morris finding him twice for dunks in crunch time Wednesday.

“Every day he learns and comes in with new dose of energy and his game develops every day we’re out there,’’ Gibson said. “He shocks me every day. He’s grown and understands the seriousness of the game now. He’s not just going out there playing.”

At some point this season, the pupil should replace the master as starting center, probably when the 21-year-old stops picking up silly fouls.

“That’s going to come,’’ Gibson said. “He understands the main thing is awareness. He watches film. He’s frustrated sometimes when he messes up. He understands we need him on the court and not fouling in the game.”

As a starter, Gibson is bringing a little of everything — rebounding on both ends, defensive grit and some scoring punch. The USC product is averaging 9.1 points and 6.1 rebounds in 19 minutes as a starter. As a bench player, he was at 2.8 points and 2.3 rebounds in 12 minutes. There were also two consecutive games when he did not play at all.

“He’s just solid,’’ Fizdale said. “This isn’t his first rodeo. He’s comfortable in all these roles. Whether you play him, don’t play him, start him, bring him off the bench. It doesn’t matter to him. He never gets messed in the head.”

“I just pay attention to detail,’’ Gibson said “Start the game off right, have the team moving in the right direction early in the game and set the pace. I just want a good start for the team and do my job.”

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