De La Rosa (7-3) registered his fifth victory in six starts, surrendering two runs on six hits. The left-hander issued a pair of walks and struck out five as the Rockies took two-of-three from the Dodgers.
Fowler's solo homer leading off the first inning gave the Rockies a quick lead and his two-run blast in the sixth provided the final margin of victory.
The Dodgers' Matt Magill (0-1) handed out nine walks over six innings in his first major-league loss. The rookie right-hander was lit up for seven runs (six earned) on five hits.
Skip Schumaker had two RBI for Los Angeles.