The result allowed San Antonio, which defeated Sacramento earlier in the evening, to clinch the No. 1 seed in the Western Conference. Los Angeles failed to expand its two-game lead over Dallas in the race for the No. 2 seed in the West.
Ellis scored 26 points while Lee had 22 points and 17 rebounds in bringing the Warriors their third straight victory.
Golden State had a four-point lead with 8 minutes to go in the third period, and then outscored Los Angeles for the rest of the quarter 18-5.
Stephen Curry added 20 points for the Warriors, who won despite shooting just 39 percent from the field.
Kobe Bryant had 25 points for the Lakers and Pau Gasol had 18. Derek Fisher and Ron Artest combined to make just 3-of-16 shots from the field for Los Angeles.