The Giants completed a four-game sweep of the Rockies to move closer to the National League West title. San Francisco is in position to clinch the division crown as early as this weekend.
Sandoval hit a solo homer in the first inning and then delivered the key blow during the big San Francisco fourth that gave the Giants an 8-2 lead.
Barry Zito (13-8) gave up just two runs in 5 2/3 innings to get the win. He consistently worked his way out of trouble while allowing 10 hits.
Jorge De La Rosa (0-1), in his ninth major-league season but making his first appearance of 2012, gave up six runs on seven hits over 3 2/3 innings to take the loss. He missed almost all of this season due to arm surgery.