Douglas believes the development of Houston's bench players will be important as the season progresses. Houston's reserves had a season-high 59 points on Tuesday, compared to just 20 by the Lakers' bench.
"That's going to be key, and that's only going to make us more dangerous," he said.
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Your drama-a-day Los Angeles Lakers were back at it Tuesday, writes Dave McMenamin. Story
The Lakers had a 13-point lead with less than 10 minutes to go. But Houston used two big runs, including a 9-2 spurt capped by a 3-pointer from Douglas to take its first lead of the game -- 100-99 -- with about 2 1/2 minutes left.
Dwight Howard made three free throws after that, but a bucket by Smith and four free throws by Houston put the Rockets back on top 106-102. Kobe Bryant hit a 3-pointer with 13.3 seconds left to cut the lead to one.
Bryant fouled Douglas and he made one of two free throws with 8.8 seconds left. The Lakers had a last chance, but Bryant missed a 3-point attempt before Metta World Peace missed a layup to give Houston the win.
Harden finished with 15 points and a career-high 10 rebounds, but entered the fourth quarter with just eight points after shooting 2 of 18 through the first three quarters. Jeremy Lin also struggled offensively, going 2 of 8 for four points.
"We had a lot of guys struggle, but our bench was good," Sampson said. "There is a lot to be said about ... having guys on the bench that you trust that can come through. Toney Douglas, Greg (Smith) and Carlos (Delfino), those three guys are special. They were tough for us tonight."
The win is Houston's fifth in the last six games and drops the Lakers to 3-5 under new coach Mike D'Antoni.
Bryant led the Lakers with 39 points and Howard had 16 points and 12 rebounds. The Rockets fouled Howard repeatedly in the last 3 1/2 minutes, gambling that sending him to the line would be better than allowing the Lakers to get the ball in Bryant's hands.
Howard went 5 for 10 from the line in that stretch and was eight of 16 overall.
D'Antoni balked at the notion that he should have taken Howard out so the Rockets couldn't use that strategy.
"If you take him out now, then you'll be taking out a guy that's going to be your franchise player all the time," he said. "We've got other problems to worry about. We shouldn't be talking about him. He's doing a (heck) of a job and he'll work through it and knock them down."
Howard also didn't like being questioned about his free throw shooting.
"People are going to say whatever they want to say, but at the end of the day, go back and look at the game," he said. "The reason we lost was not my free throws. That didn't lose us the game. Our defense was not there in the fourth quarter."
Los Angeles led by 13 before Houston used a 14-4 spurt to close the gap to 94-91 with five minutes left. The Lakers had six turnovers and missed five shots in that span. Bryant finally got Los Angeles going again with a free throw and a bucket to make it 97-91.
The Lakers were playing without forward Pau Gasol, who sat out because of tendinitis in both knees. Antawn Jamison started in his place and had 15 points and nine rebounds.
"You miss him a lot," Bryant said of Gasol. "He's a dominant player. He's an excellent passer, an excellent post player and an excellent shooter. We're missing a lot."
A 9-0 run by the Rockets, which included five points from Delfino, got them within 75-68 with about four minutes left in the third quarter.
The Lakers led 83-73 entering the fourth quarter after Bryant hit a fadeaway jumper as the quarter ended.
The Rockets scored six straight points to get within seven points with 10 minutes left in the third quarter. The Lakers answered with a 7-2 run to push the lead to 67-55 with about eight minutes left in the quarter.
Houston cut the lead to six points with a 3-pointer by Delfino early in the second quarter before the Lakers used a 10-3 run to extend their lead to 46-33 about five minutes before halftime. That run was capped by a dunk by Howard followed by a 3-pointer from Jamison.
The Lakers led 58-45 at halftime.
The Rockets are paying tribute to coach Kevin McHale's daughter Alexandra "Sasha" McHale, who died on Nov. 24 at age 23 of complications from lupus, by wearing a green and purple band on their jerseys and a patch of the same color with her initials on their warm-up shirts. Green was her favorite color, and purple is the color that represents the fight against lupus. McHale remains on leave indefinitely. ... Houston's Chandler Parsons scored 13 points for his 10th straight double-digit game. ... Jamison had a season-high three blocks.
Entering tonight, the Lakers were 597-9 in games they led by 10 or more points in the final 8:00 of the 4th quarter since Kobe Bryant's rookie season.
Using that probability, the Rockets had roughly a 1.5 percent chance of winning.