Playing 26 minutes, Bryant grabbed a team-high nine rebounds. He was also hit with a technical foul for arguing a call with the replacement referees.
In his first game with the Lakers since signing in the offseason, Ron Artest started at small forward and had 12 points, nine rebounds, seven assists and five fouls.
With Bynum active underneath, the Lakers jumped out to a double-digit lead in the first quarter at the Honda Center, pushed it to as many as 25 points in the third quarter and were never seriously threatened.
Bynum shot 8 of 12 from the field and 8 of 9 on free throws.
Anthony Morrow overcame a slow start to score 15 of his 25 points in the fourth quarter as the Warriors fell to 1-1. Forward Anthony Randolph added 18 points and 12 rebounds, and rookie guard Stephen Curry, the No. 7 overall pick, finished with 11 points off the bench.
The Warriors played without guard Kelenna Azubuike, who was out with a sprained ankle. Then they lost starting guard Monta Ellis less than 2 minutes into the game when he sprained his left ankle after he stepped on a camera man. He did not return.