Nowitzki scored a season-high 35 points and Butler hit a pivotal 3-pointer late in the game, helping the Mavericks hold off a Nuggets squad missing center Nene 102-101 on Wednesday night.
"It comes down to one possession either way: You're going to walk out of here feeling great or terrible," Mavs coach Rick Carlisle said.
Butler, who finished with 16 points, did his best to make sure Dallas didn't deal with dejection. He caught the ball in the corner and hardly hesitated before releasing a 3-pointer with 2 minutes remaining to give the Mavericks a 102-99 lead.
The Mavs made it hold up.
"Tough, tough shot," Chauncey Billups of the Nuggets said as he shook his head.
Carmelo Anthony answered Butler's basket with a dunk to trim the lead to one and after a Mavericks shot-clock violation, the Nuggets had one last chance.
But Anthony's 22-footer with Shawn Marion in his face rimmed out and the Nuggets couldn't track down the rebound in time.
"That's Melo's shot. He's won a lot of games with that shot," Nowitzki said. "We were a little fortunate."
It's a shot Anthony said he makes 90 percent of the time.
Just not Wednesday.
"It's a heartbreaker, but you make some and you miss some," said Anthony, who finished with 20 points and 15 rebounds. "Especially in a game like this, a chance to win the basketball game, you see it in the rim and it comes out. That's a shot I'll take on any give night."
With Nene sidelined by a strained left groin and forwards Chris Andersen and Kenyon Martin still out after offseason knee surgeries, the Nuggets had to go with a smaller lineup, giving rookie forward Gary Forbes his chance.
Forbes, who spent last season playing in the Philippines and Israel, finished with 12 points, all in the first half.
If the Mavs knew nothing about him Wednesday, they will in three days when the two meet again in Dallas.
"They got a little hint tonight," Forbes said, smiling.
The Nuggets went with a cast that included no one over 6-foot-9.
That made covering the 7-foot Nowitzki and 7-1 Tyson Chandler awfully tricky.
"Dallas is a very difficult match up with when you're 100 percent," said Nuggets coach George Karl, whose team was outrebounded by a 45-39 margin. "We fought hard, had a lot of pride, a lot of will. We just came up short."
Forbes even took his turn attempting to guard Nowitzki. It's a job that's usually reserved for Martin, who may not be back until around the first of the year.
But he burned anyone the Nuggets assigned.
"We went into the game saying that's what we were giving up," Billups explained. "Our key was to try to keep them from hitting a lot of 3s on a double team. ... I said all along, if we can keep them off the 3-point line, and make (Nowitzki) make those tough shots, we had a chance."
That's where Jason Terry factored in. He scored 16 of his 20 points in the third quarter, including four 3-pointers, to help the Mavericks build a lead that stretched to as many as 11 points.
The Nuggets went on a run late in the third to pull within 84-80.
It was back and forth from there.
"Definitely a grind-out kind of game," Nowitzki said. "Heck of a win."
In the first half, it was Denver who saw a double-digit lead crumble. The Nuggets led by as many as 10 points in the second quarter, but the Mavs closed within 52-50 on a shot by Nowitzki just before the halftime buzzer.
The All-Star averaged 21.3 points against Denver last season and nearly had that at halftime, scoring 20 points, most coming on mid-range jumpers and running hooks inside the lane with no Martin, Andersen or Nene around to contest the shots.
Nene was scratched just before tip after being bothered by a groin injury that surfaced near the end of a win over Houston on Saturday.
He's listed as day-to-day.
Harrington, who finished with 16 points, nearly signed with the Mavs in the offseason, before selecting Denver. ... Andersen has been running fastbreak drills and the team remains hopeful he will return before Dec. 1. ... Dallas G Jason Kidd had 12 assists.