DALLAS — Luka Doncic was the only star on the floor for Thursday’s Nets-Mavericks game, and he did what he was supposed to do.

Amid chants of “MVP! MVP!” Doncic shook off foul trouble and shrugged off the Nets en route to Dallas’ 123-111 win. He took over in the fourth quarter and handed the Nets a season-worst fourth straight defeat.

Doncic had 15 of his game-high 31 points in the final period on 5-of-7 shooting, turning what had been a one-point Nets lead into a stinging defeat.

“It’s hard when you don’t get stops. … Our defense, we never found a way to stop him,” Nets coach Kenny Atkinson said. “You’ve got to take advantage when their best player is out of the game. You’ve got to do a better job of getting separation. We didn’t.”

The Nets — who blew a 10-point cushion — still led 96-95 when Doncic checked in with four fouls and 10:33 to play. He promptly sparked an 11-4 run, his 30-footer giving the Mavericks a 106-100 edge they never lost.

Speaking of losses, the Nets fell under .500 at 16-17.

“We’re in a little bit of a rut right now,” Atkinson said. “We’ve been through this before.”

Discounting their playoff sweep by the 76ers, it’s their longest losing streak since last season’s eight-game skid that left them 8-18 on Dec. 5

Kyrie Irving still is not practicing, but with Caris LeVert (thumb) expected to return Saturday versus Toronto — the opponent that sparked last season’s turnaround — can they mount another as an encore?

“You don’t want to continue to lose or drop games,” said Spencer Dinwiddie, who had 19 points and five assists despite foul woes.

Garrett Temple was out with a sore knee, so Atkinson gave Rodions Kurucs the nod on the wing and handed DeAndre Jordan (10 points, 10 boards) his first start since Nov. 2.

It paid early dividends. The Nets clogged driving lanes and ran out to a quick 13-3 lead behind a left-corner 3-pointer by Kurucs.

Naturally, Dallas responded, even with Doncic taking a breather on the bench. With the Nets leading 18-10, they gave up a 17-9 run as Dallas pulled even — and the game got feisty.

Dinwiddie chased down Doncic on what appeared to be an easy layup to deliver a hard foul. Later, Maxi Kleber (18 points) knocked Jarrett Allen down, and Taurean Prince shoved the Maverick in retaliation, with both getting technicals.

The Nets led by 10 with 1:21 left in the half and were ahead 67-64 early in the third before a 12-4 Dallas run. Seth Curry scored 15 of his 25 points in the third and Kleber’s 3-pointer put the Mavericks up 76-71.

That’s when Doncic picked up his fourth foul, going out with 6:47 left in the third. But while he was sitting, the Nets only managed to grab a 96-95 lead before he came back and snatched it away.

Back-to-back baskets by behemoth Boban Marjanovic made it 103-98, and Doncic’s long 3 left the Nets in a 106-100 hole.

With the score 108-104, the Nets coughed up eight unanswered points. Doncic hit a step-back 3 and after grabbing a rebound drove for a layup and 116-104 cushion. The clock read 3:48, but the game was over.

“It’s tough because you try and take advantage of it when he’s on the bench, but even when he was on the bench it’s still like we were just matching,” Joe Harris said.

“If it wasn’t Curry or Kleber or someone else they just continued to execute really well offensively, got baskets and we were just matching them basket-for-basket. Then Luka came in and they started getting offense from him and we weren’t able to get stops.”