DENVER -- The Denver Nuggets are starting to see the storm clouds closing in on them.
"It's not raining," Nuggets coach George Karl said. "It's just cloudy."
Denver had a chance to tie idle Utah atop the Northwest Division after losing their grip on first place 24 hours earlier with a disheartening loss at Sacramento. But they fell behind by 19 points in the third quarter and couldn't overcome big games by Ron Artest (22 points) and Aaron Brooks (19).
Before tip-off, Karl said he still thought the schedule down the stretch favored Denver, which he thinks can recover and get home-court advantage in the first round. But the Nuggets, who were the No. 2 seed in the West at the All-Star break, have slipped all the way to seventh in the convoluted conference.
"The clouds will go away, the sun will come up again," Karl insisted.
"I don't think there's anyone in that locker room that's afraid of the challenge that we have," Karl said. "It's just the funk of not playing very well for seven, eight games. I'm not going to make excuses, but there seems to be at times to be a mental fatigue to our team."
Denver led by 10 early, but blew a double-digit lead for the third time in their last five games.
The Rockets secured their 11th win in 13 games since Tracy McGrady's season-ending knee injury with another night of great teamwork.
"We're going to win together or lose together," Artest said. "I'm not winning this thing by myself. Yao's not going to win by himself. You're either going to win with your team or lose with your team. It took a lot of years to understand that. But that's how it's going to be."
The Nuggets have sorely missed Martin (back) and guard Anthony Carter (hip). Martin, who missed three games with a bad back, had to take a seat in the third quarter when it tightened up on him again, throwing his status back into doubt.
The Nuggets were counting on his return to get them back on track both offensively and defensively. But after logging 24 minutes, scoring six points and pulling down seven boards, Martin took a seat for good with 4:18 left in the third quarter and the Nuggets trailing 65-49.
"It seems like when he plays and comes out and tries to go back in, it's harder to get it loose," Karl said. "The back is ... I was a bad back guy. It's not fun. You can be in spasms and the doctors can't tell you why. Then the next day you wake up and the chiropractor cracks you and you're fine. The back is not a good injury."
Shortly after Martin's exit, Artest sank a 3-pointer to give Houston its biggest lead at 68-49.
The Nuggets chipped away and made it exciting by pulling to 92-90 on Nene's basket with 23 seconds left.
The Rockets, the league's third-best free-throw shooting team, kept the Nuggets' hopes high by shooting just 20-of-35 from the free-throw line.
"That's unusual," Rockets coach Rick Adelman said. "We usually don't miss free throws like that."
"That is very strange," Artest concurred. "But that was our fault. We were up so big. That's our next step right there, being able to keep a team down. We make those free throws we win by 10, nine points."
They did make their free throws when they had to, sinking five of six in the final 22 seconds.
Brooks hit one of two free throws to give Houston a 93-90 lead. Chauncey Billups, who led the Nuggets with 28 points, missed a layup at the other end, and Kyle Lowry sank two free throws with 9.9 seconds left.
After Billups' bucket made it 95-92, Brooks sank two free throws, rendering moot J.R. Smith's 34-footer at the buzzer.
Martin said his back started hurting again in the first quarter, and "I just tried to tough it out. It didn't respond to anything we did during the game or at halftime. It's frustrating."
He said he'll get treatment Tuesday and will try again to play Wednesday night against Oklahoma City, but "I just don't want to keep going out there and not finishing games."
Billups said it wasn't all doom and gloom in Denver, suggesting there was a silver lining to this latest loss.
"Other than a couple stretches, I thought we made some strides," Billups said. "The thing is when you're struggling and you've worked yourself into a rut like that, you can't just turn on a switch and it's over. You've got to work yourself out. You've got to get better. It's a process."
Denver matched its longest losing streak (three) of the season. ... Nene shot 4-for-15, falling behind Shaquille O'Neal for the league lead in shooting percentage.