DENVER – It was the start of the NBA’s in-season tournament, but when you got past the eye-challenging court and all the talk about meaningful games before Christmas, one thing remained unchanged.

The Mavericks were not going to go 82-0.

That they made it to 4-0 was impressive, but the NBA’s list of unbeatens dropped to one (Boston) as the Mavericks dropped a 125-114 decision to the Denver Nuggets Friday night at Ball Arena.

It was a game in which the Mavericks simply never could gain any traction, trailing virtually the whole way and usually by double figures.

The Mavericks welcomed back Kyrie Irving after he missed two games with a left foot issue. And he had a solid return (22 points), giving the Mavericks some much-needed punch on a night when their battle was severely uphill.

Nikola Jokic was spectacular with 33 points, 14 rebounds and nine assists. So was Luka Dončić with 34 points, 10 rebounds and eight assists. But he also had nine turnovers. That the Mavericks fell behind 40-24 after the first quarter didn’t help, either.

“We started slow, but there’s a lot of positive things to look at,” Dončić said. “What lost us the game is my turnovers and the defensive rebounds. I think if this was last year, we would have lost by 30.”

Asked about his turnovers, he said: “It was terrible. Just sloppiness with the ball. Trying to make passes. A lot of them (weren’t) good decisions. I got to get way better. I think I started the season very low on turnovers but kind of sloppy with the ball the last couple games.

The Mavericks got no closer than eight points down the stretch. They could not come up with enough stops or rebounds to make it more interesting.

They were outrebounded 51-34 after being very respectable on the glass through the first four games.

“It was a confluence of circumstances,” said Sean Sweeney, who was acting head coach while Jason Kidd remained in Dallas with a non-COVID-19 illness. “There’s a number of guys they have that crash. Their positioning puts guys around the rim a lot and they have a number of guys who chase their own misses.

“When teams take those tough intermediate paint shots, often times from the perimeter you have to make a real point to come in and help rebound instead of watching one of your teammates go one-on-one with a bigger guy down there.”

After falling behind 40-24 after the first quarter, it was a major uphill climb.

“The guys did a great job of trying to fight,” Sweeney said. “When you start down that much early on, we all know it’s tough to overcome that.”

And so, the Mavericks are 0-1 in their Group B pod with in-season tournament games left against Houston, New Orleans and the Los Angeles Clippers.

But seeing Irving back in the lineup after missing the past two games was one of the positives to take out of the game.

“A little rusty to begin the game,” Irving said. “We’re in Denver, a mile above sea level. I knew it was going to be interesting tonight just going against a well-oiled machine.

“It’s always tough to win in Denver so we knew it was going to be tough. They showed why they’re great. I think we can take this kind of butt-whipping in the first half and really learn some things. We had a good last three quarters. We can take some positives.”

The Mavericks had the misfortune of catching the Nuggets after they got sideswiped by Minnesota on Wednesday, dropping a 21-point decision.

The Nuggets didn’t win the NBA championship last season by piling up a bunch of losses.

“When you have the goals we have in mind, you challenge yourself to stop a losing streak at one,” coach Michael Malone said pregame. “You never want it to go to two or three or four.”

And the Nuggets played with a degree of urgency from the start. The Mavericks played better after the first quarter, but could not shave points off the Nuggets’ lead fast enough.

Through halftime, the battle of the superstars was tilted squarely in Denver’s favor. Jokic got pretty much whatever he wanted in the paint and finished the first half with a buzzer-beating three-pointer that provided the 15-point cushion.

Dončić had 12 points, five assists and four rebounds in the first half. But he also had six of the Mavericks’ 10 turnovers.

And they were getting hammered on the boards, which was something that never changes.