Rockies 6, Giants 1: Todd Helton and Charlie Blackmon homered and Juan Nicasio pitched six shutout innings as host Colorado defeated San Francisco.

Nolan Arenado went 3-for-4 and scored twice as the Rockies won the opener of the three-game set. Nicasio (8-6) added a run-scoring single and matched a season best with nine strikeouts while allowing four hits and two walks.

Helton hit a two-run blast in the second inning - his 2,497th career hit - and Blackmon hit a solo shot in the third off Giants starter Barry Zito (4-10). Nicasio’s fourth-inning single made it 4-0 and Blackmon drove in a run later in the frame on a fielder’s choice.

Colorado boosted the lead to six in the seventh when DJ LeMahieu reached on an infield single and reliever Jose Mijares made a wild throw to first, allowing Corey Dickerson to score from second.

Zito allowed five runs and nine hits in four innings while losing his seventh straight decision. Joaquin Arias doubled in the lone San Francisco run with two outs in the ninth.

GAME NOTEBOOK: Rockies CF Dexter Fowler left after the first inning with a bruised left knee. … Colorado SS Troy Tulowitzki (ribs) missed his second straight game. ... Nicasio fell one shy of his career high for strikeouts. He fanned 10 against the San Diego Padres on July 31, 2011.