The Rockies won their fourth straight series after beating San Diego, Philadelphia and San Francisco.
De La Rosa (2-3) allowed a run and four hits. The left-hander has won his last three starts against the Dodgers after going 0-8 with a 7.32 ERA in his 10 previous career starts against them.
Pitcher Hyun-Jin Ryu’s two-out single in the second inning was Los Angeles’ last hit until Matt Kemp doubled to right-center with two outs in the eighth against Adam Ottavino.
Ryu (3-2) gave up six runs and nine hits in five-plus innings. The Korean-born lefty is 0-2 with a 9.69 ERA in his three starts at Dodger Stadium, but 3-0 with a 0.00 ERA in four road starts.