DENVER — Twice, the Dallas Mavericks have turned games against the Denver Nuggets into fourth-quarter scrums.

Twice, the Mavericks have flopped, and not by faking fouls, like the Nuggets have accused them of.

The Mavericks were wiped out in the fourth quarter by Carmelo Anthony, Nene and Co, slapped with a 117-105 loss Tuesday night that put them in a 2-0 hole in the Western Conference semifinals series.

The Mavericks must win four of five against the Nuggets if they are to extend their season. The best-of-7 series continues Saturday at American Airlines Center.

Their collapse Tuesday was eerily similar to the pitfall they had in Game 1, except this time they had less firepower after Josh Howard went down with a right-ankle sprain and missed the final three quarters.

Still, the Mavericks were within 86-83 going into the fourth quarter. In Game 1, they were within 82-80 early in the fourth.

This time, the Nuggets outscored the Mavericks, 16-2, to go ahead, 102-85, with 6:26 left and end the drama shortly after midnight Dallas time.

About then, the Pepsi Center crowd opened up chants of "You can't beat us." And how right they were, so far, at least. Even a silver-bullet effort by Dirk Nowitzki and lots of support from the bench couldn't lift the Mavericks.

They were fighting from behind most of the first half, but were down just 58-55 at the break, thanks to what was essentially a six-point play in the final seconds.

J.R. Smith had tortured the Mavericks in the half, scoring 17 points. But he clanked a 3-pointer with five seconds remaining, and Kidd scooped up the rebound. He raced downcourt and pulled up and swished a 26-footer as the buzzer sounded.

Instead of potentially being down 61-52, the gap was only three.

The Mavericks had played the Nuggets on even terms for 24 minutes and even though they found out Howard would miss the second half, they came out with a hard-nosed attitude in the third quarter.

Jason Terry was throwing in 3-pointers, and Nowitzki was pounding the Nuggets with an assortment of jumpers, drives and trips to the free throw line.

It was Terry's 3-pointer with 5:20 left in the third that put the Mavericks up for the first time since the first quarter, 74-72.

From there, it was a matter of whether they could handle the Nuggets' physical play and the raucous Pepsi Center crowd.

In Game 1, the Mavericks didn't. The Nuggets blew open the game down the stretch, opening the door for some interesting byplay between the teams before Game 2.

The Nuggets had accused Nowitzki of flopping on some of his plays in Game 1, particularly when Kenyon Martin gave him a shove to the hardwood when Nowitzki drove to the basket in the first quarter.

Martin got fined $25,000 for the act. Now Nowitzki's getting jabs from long-forgotten NBA players.

Before Game 2, Denver vice president of player personnel Rex Chapman had called Nowitzki "a good actor," to which Nowitzki responded at the Mavericks' morning workout, "I didn't know Rex Chapman was still alive.

"I don't think I am necessarily an actor. I try to play hard, and that's about it."

There was nothing insincere about the end of the third quarter as Nowitzki scored the Mavericks' final five points to keep them in Denver's shadow, down 86-83.