A potential trip to Las Vegas wasn’t enough to get the Nuggets to dial up their defense.

With the winner of Friday’s game against San Antonio at Ball Arena winning NBA Cup Group C and moving within a win of the semifinals in Sin City, Denver’s defense didn’t show up for three quarters in a 139-136 loss to a Spurs team that had the last two Rookie of the Year winners, Victor Wembanyama and Stephon Castle, sidelined with injuries.

San Antonio scored 36 or more points in three of the quarters. The exception was the Spurs’ 18-point second quarter.

“The second quarter, I thought we sat down and guarded. I thought we were really physical in that quarter,” Nuggets coach David Adelman said. “I thought the other three, we just played a pickup game with them. So, when you score 136 points and lose, that’s an issue. So we’ve got to shore some things up, got to compete better on that end.”

The Nuggets remained without Christian Braun and Aaron Gordon, and the shorthanded Spurs took advantage of a Denver team down two of its best defenders. Devin Vassell scored 35 points on 12-of-17 shooting, and Justin Champagnie made three 3-pointers and all 10 of his free throws to chip in 25 points. Five other Spurs scored in double figures, including De’Aaron Fox, who used his quickness to get into Denver’s defense and dish out 12 assists to San Antonio’s shooters, especially in single-side pick-and-roll set looks where one defender has to choose between helping on the roller and guarding their man in the corner.

“You see a big rolling, a 7-footer rolling, you don’t want to just leave him there. Then, with a guard like Fox who’s able to kind of hold a defense … you try to put ball pressure on that guy, so that he can’t see the passes or make him make a quicker decision or rush him,” Nuggets wing Cam Johnson explained. “When you have good guards like that, that are able to just be patient, you can’t really speed them up, they’re able to pick you apart a little bit. That single-side tag is just trying to protect the basket a little bit.”

San Antonio finished the night 17 of 42 (40.5%) from 3-point range.

Jamal Murray led the Nuggets with 37 points on 13-of-20 shooting and surpassed 10,000 career points with a driving layup in the opening minutes. Johnson had his highest-scoring game of the season with 28 points on 10-of-16 shooting, while Nikola Jokic (21), Peyton Watson (15) and Tim Hardaway Jr. (15) also scored in double figures.

After the defensive collapse, Denver has failed to advance to the NBA Cup’s knockout stage in the first three years of the in-season tournament.

“It was everybody tonight,” Adelman said. “They scored 139 points. So, whoever the hell I put out there, they were scoring baskets. We just got to be better defensively.”

SPURS 139, NUGGETS 136

What happened: San Antonio led by eight after the first quarter, but Denver owned a 74-59 advantage at halftime. The Spurs closed within a point to start the fourth and put the Nuggets away in the final minutes.

What went right: Denver’s defense showed up in the second quarter. San Antonio scored just 18 points on 8 of 26 shooting from the field, including a 1-for-8 mark from 3-point range.

What went wrong: The Spurs made 13 of the 14 shots they attempted inside the arc and scored 41 points in the first quarter. San Antonio dropped 44 more points in the third.

Highlight of the night: Nikola Jokic threw his nightly behind-the-back pass assist, but Cam Johnson got it done on both ends during Denver’s second-quarter run. Johnson poked the ball away from Harrison Barnes, recovered the loose ball and threw down a one-handed slam on the other end.

Up next: The Nuggets flew to Phoenix after Friday’s game for Saturday’s 7 p.m. tipoff against the Suns.