DENVER — The Dallas Mavericks' plan to play with more hustle and muscle worked wonders until Jason Kidd's bad pass late in the third quarter dribbled back downcourt last night.

Instead of watching it go out of bounds, Denver point guard Chauncey Billups made a beeline for the ball. He beat Jason Terry to it, then whipped it to J.R. Smith under the basket for the go-ahead score.

Game over.

Denver didn't trail again after Smith's bucket, which sparked a 117-105 victory that gave the Nuggets a 2-0 lead in the best-of-seven series that shifts to Dallas this weekend.

"That was the key play of the game," Denver's Carmelo Anthony said. "He could've easily just let that ball go out of bounds, he chased it down, got J.R. the layup. We came down and we scored again and again and again. That play right there was the biggest play of the game."

Anthony scored 15 of his 25 points in the fourth quarter, including 10 in a 16-2 spurt the Nuggets used to start the quarter and break open a close game.

Billups said he never thought of just letting the ball go out of bounds or letting Terry beat him to it for a momentum-stuffing backcourt violation instead.

"Those are absolutely the kind of the plays you've got to make," Billups said. "If you don't make them, just try — 100 percent effort. ... That was a big play."

And it was deja vu for the Mavericks, who also collapsed in the fourth quarter of Game 1.

"I thought we were right there again like we were the other night and just things with this team can get out of hand quickly," said the Mavs' Dirk Nowitzki, who scored 35 points.

"They're so explosive. I think we kept the turnovers down but right there in that phase where they made their run, we had two or three costly ones and took two bad shots. The next thing you know, from a four-point lead it's 14. That's how explosive that team is."

Nene scored 25, Smith had 21 and Billups 18 for the Nuggets, who won for the 15th straight time at the Pepsi Center, where they haven't lost since March 11.

The Mavericks are 17-1 at home since the All-Star break, but that one loss was to Denver.

The Mavericks now face the daunting task of having to win four of five against the Nuggets, a team they're 0-6 against this season and one that is playing with so much confidence and efficiency.

"They've held serve," Dallas coach Rick Carlisle said. "We go back to Dallas and we've got to do the same. We've got a few days to regroup and work on some things."

The Nuggets, whose six postseason wins have come by an average of 24.8 points, broke open a back-and-forth game by starting the fourth quarter on a 16-2 run, sparked by Anthony's 10 points, to take a 102-85 lead.

"We're just an explosive team in that way," Billups said. "That's who we've been all year."