PHOENIX — Call him the sleepless Knicks starting point guard.

Elfrid Payton became a new father Thursday but didn’t want to miss a game because of the milestone.

With his girlfriend giving birth to a baby girl at 9 a.m. on Friday, Payton, who missed the team flight to Phoenix on Thursday, flew out Friday afternoon in time for the game.

The Knicks had called Payton’s absence “personal reasons’’ as the former Louisiana-Lafayette point guard wanted to keep it quiet.

He showed up at the Talking Stick Resort Arena 80 minutes before tip-off and having missed the morning shootaround.

Incredibly, Payton notched 15 points with six assists and five rebounds.

“It was tough — I barely got sleep,’’ Payton said after the 120-112 loss. “I was up basically all night. Nothing was routine about today. I appreciate my teammates sticking with me.’’

Payton said he had a few conversations with Knicks brass on whether to rush in.

“We definitely talked about it with the front office,’’ Payton said. “We decided to get it done.’’

“Really it was his choice,’’ interim coach Mike Miller said. “He wanted to be here. We’re all excited obviously to see how committed he is to his team, his teammates, how much he wants to play.”

Payton started the game 3 of 3, getting easily to the basket, so the hectic day didn’t bother him early.

“He’ll have plenty of time to warm up,’’ Miller said before Payton arrived. “His shooting time is at the end, so he’ll get his full shooting time and full warm-up. He’ll get his normal pregame workout routine in.’’

Owner James Dolan is making the Knicks’ West Coast trip and was in the locker room beforehand the Phoenix game. Dolan — who owns the Forum, the Lakers’ former home — does business in Los Angeles, where the Knicks will be for four nights, playing the Clippers and Lakers at Staples Center.

Dennis Smith Jr. missed his fourth straight game with a strained oblique.

One year ago, even before groin issues derailed his season, Knicks point guard Frank Ntilikina was experiencing a rough patch with former coach David Fizdale.

From Jan. 4 to Jan. 11, 2019, Ntilikina was benched, absorbing four straight “DNP-CD.” By late January he was all but done for the season with a groin injury that never healed.

The start of 2020 for the 2017 lottery pick has been a blast. Late in the fourth quarter against Portland on New Year’s Day, he zoomed down the right side and soared in for a monster right-handed jam. The usually stoic Ntilikina raised his arms into the air as the Garden crowd went wild.

“It was a good moment, a good reaction,’’ Ntilikina said before scoring six points to go with two assists and two rebounds against the Suns on Friday night. “I felt the game as over at that time. It was not a celebration — just being happy to get the win.’’