Yao Ming, who briefly left with a knee injury in the closing minutes, had 28 points and 10 rebounds to lead the Rockets to a physical 100-92 victory in Game 1 of the Western Conference semifinals.
Ron Artest added 21 points and Aaron Brooks had 19 for the Rockets, who are in the second round since 1997.
Bryant, who finished a distant second to LeBron James in NBA MVP voting announced earlier Monday, scored 32 points, doing his best to keep the Lakers in the game despite missing practice on Sunday with a sore throat. He scored 22 of the Lakers' final 42 points.
Houston forward Shane Battier needed four stitches to close a gash over his left eye late in the first quarter.
Although the Rockets took the brunt of the hits, Yao was too much for the Lakers. The Rockets were much livelier on offense and wrested away homecourt advantage from the top-seeded Lakers.
Game 2 is Wednesday night in Los Angeles.
Bryant drove on Yao in the key and the two collided, with Yao falling to the court. Los Angeles' Pau Gasol picked up the ball for a slam dunk that pulled the Lakers to 85-79 with 4:54 left.
Yao grabbed his knee and grimaced in pain as he sat on the court. After being tended to, he limped off the court. Moments later, after stretching his knee in the tunnel, he was back in the game.
Yao had eight points after coming back; a jumper and six free throws. He made all 10 of his free throws.
Battier was cut over his left eye and had blood streaming down his face in the closing seconds of the first quarter. He was hit when Los Angeles' Sasha Vujacic swatted a loose ball out to Bryant. The force of the impact knocked Battier to the ground.
Workers spent a few minutes wiping blood off the court.
Battier returned late in the second quarter.
Earlier in the quarter, the Lakers' Pau Gasol had trainers work on a cut over his left eye, and Gasol returned to the game, finishing with 14 points and 13 rebounds.
The Lakers trailed 59-50 with just less than 6 minutes left in the third quarter after Artest hit a 3-pointer. Bryant scored 11 of the Lakers' last 14 points in the quarter, which ended with the Rockets ahead 70-67.
Bryant made three jumpers in just over than 2 minutes, helping keep the Lakers close as both Yao and Brooks drove the baseline for dunks.
Notes: Andrew Bynum of the Lakers started but drew two fouls in the first 3 minutes and was replaced by Lamar Odom. ... The Lakers were 4-0 against the Rockets during the regular season.