The Nets’ regular-season finale had a low-key summer league vibe. Until another huge Cam Thomas outburst turned it interesting.

The gifted young guard almost single-handedly pulled out Sunday’s game, with Brooklyn sitting nine players and falling to Philadelphia 134-105 before a sellout crowd of 17,732 at Barclays Center.

Given the greenest of green lights, Thomas poured in 46 points, just one shy of his career high.

With the teams set to face each other in the playoffs, they sat a combined 16 players in a game that had a preseason atmosphere — until pride took over and the 76ers starting doubling Thomas down the stretch.

“Yeah [I was surprised]. Yeah, because I’m like, ‘If y’all are going to double, y’all should’ve did it when I had like 30 in the third, cooking. But y’all want to do it with like a minute or two so I can’t get 50? So I was surprised, but it is what it is.”

Thomas finished 16-for-29 from the floor, and 6-for-8 from deep.

He poured in 29 points in the third quarter on 7-for-8 shooting before being held to just four in the fourth.

Want to catch a game? The Nets schedule with links to buy tickets can be found here.

“I saw their bench pointing to Paul Reed, telling him to come trap. I just started pointing at him, laughing, like, ‘Y’all look bad right now. Double with a minute left?” And he goaltended and they didn’t call it, so I was like, ‘Aw, man,’ ” Thomas said. “But it is what it is, final game, last game of the [regular] season. We have another season coming up, so hopefully we can get them then.”

Once the threadbare 76ers — who sat their top seven players — started doubling Thomas, the Nets (45-37) had no other answers.

“Yeah, they were trying to keep him away from 50,” coach Jacque Vaughn said. “So, a little pride came into play, trying to keep away from 50. And 46 is pretty good.”

The Nets shot just 42.2 percent with RaiQuan Gray — just signed to a two-way deal on Saturday — delivering 16 points, nine rebounds and seven assists in his NBA debut.

Sunday was Thomas’ fourth 40-point game, with the other three coming consecutively from Feb. 4-7.

The only players in the NBA with more such games since Feb. 1 are Donovan Mitchell and Damian Lillard.

“He’s done it before with the amount of shots, with the amount of minutes,” Vaughn said. “The ability to create at any time on the shot clock, he’s proven that.”

But has he proven enough to elbow his way into the playoff rotation?

“I don’t know,” Thomas said. “Hopefully. But that’s out of my control. That’s their decision. So I don’t know.”

Asked what Thomas has to show, Vaughn was vague.

But in essence, the second-year microwave scorer has to show he can contribute to wining.

“I wish the score was 134 Brooklyn Nets, 105 Philadelphia. That part helps,” Vaughn said. “The goal is you win as a team. So 46 points is great, but we end up losing by 30. You’ve got to attach those together.

“How do you marry the 29 shots to being a productive teammate when you might not get that amount of shots? That’s the question. So can you harness and take that ability and be able to do it in the shorter amount of time, in a more efficient time? And in a setting that it benefits the entire team? That’s the challenge.”

Thomas did help his team nearly erase a 20-point deficit, getting within five.

The Nets fell behind 48-28 with 8:05 left in the half on a free throw by Shake Milton (20 points).

But Thomas’ and-one made it 97-92 with 35.8 seconds left in the third.

He had 42 going into the fourth with the Nets down 100-92, but playing just seven men they ran out of gas.

The Nets were without Nic Claxton, Seth Curry, Spencer Dinwiddie, Dorian Finney-Smith, Joe Harris, Cam Johnson, Royce O’Neale, Ben Simmons and Edmond Sumner.

Mikal Bridges played just four seconds.

“He was almost at 50 points so they obviously don’t want to give up that to him,” Gray said with a laugh. “Great scorer, people know what you can do, so I’m sure they were a little scared about that. … [But] they shouldn’t have double-teamed.”