DENVER -- The evolution of Juan Nicasio continued Monday night.
The Colorado Rockies right-hander pitched six scoreless innings, working his way out of several jams in a 6-1 win over the San Francisco Giants.
Nicasio tied his season high with nine strikeouts, one short of the career high he set in 2011. He also drove in a run with a single in the two-run fourth that gave the Rockies a 5-0 lead and finished Giants starter Barry Zito.
Nicasio allowed four hits and two walks. He struck out Pablo Sandoval to end the first with the bases loaded and got Buster Posey to ground into an inning-ending double play with runners on first and third in the third.
In the sixth, Nicasio hit the leadoff man with a pitch for the second inning in a row, and he gave up a single to Posey. However, he regrouped, retiring Hunter Pence and Sandoval on fly balls to center, Sandoval's sending Charlie Blackmon to the wall, and striking out Brandon Crawford.
"He's come a long way in that regard, minimizing damage," manager Walt Weiss said of Nicasio. "The big one was the sixth inning, really wanted him to get through that sixth instead of having to go to the 'pen. Our guys were pretty taxed out there. I threw (five relievers Sunday) in Miami, so didn't want to go there that early.
"That was big for Juan getting through that sixth inning. He's made some huge strides since he's come back from Triple-A (in mid-July), not giving up the big inning."
Wilton Lopez struck out three in two scoreless innings, and Jeff Francis allowed a run in the ninth as the Giants avoided the shutout.
Zito, in his second start since returning to the rotation to replace injured right-hander Chad Gaudin, lasted four innings and gave up nine hits and five runs. The veteran lefty, whose seven-year, $126 million contract with the Giants will end after this season, has lost seven straight decisions, the third-longest losing streak of his career.
Zito allowed home runs by Todd Helton and Charlie Blackmon. He has given up 14 home runs in his past 13 outings. In his past five starts dating from July 14, Zito is 0-4 with an 11.21 ERA.
Helton hit a two-run homer in the second, his ninth of the season, to open the scoring. Blackmon, who entered the game in the second when Dexter Fowler left with a bruised knee, led off the third with his fourth homer.
Nicasio singled home a run with the bases loaded and one out in the fourth when center fielder Gregor Blanco charged but couldn't reach his short fly and didn't dive for it. Had the ball been caught, it likely would have been an inning-ending double play.
The Rockies added another run to make it 5-0 when Blackmon hit a potential double-play grounder that second baseman Marco Scutaro dropped, giving Blackmon enough time to beat shortstop Brandon Crawford's throw to first.
"There was bad luck in there," Giants manager Bruce Bochy said, referring to Zito's fate in the fourth. "He just left some pitches up, too, though. Couple curveballs. He was pretty good on the right-hand hitters. Lefties, he left a couple curveballs up that he paid for."
NOTES: Rockies RHP Rafael Betancourt, 38, has a partially torn ulnar collateral ligament in his right elbow. He said he will attempt platelet-rich plasma injections in hopes he can avoid Tommy John surgery. ... Colorado SS Troy Tulowitzki sat out for the second straight game due to soreness in his left side. He expects to play Tuesday. ... Rockies manager Walt Weiss said C Yorvit Torrealba could be activated Tuesday, one day after he was eligible to come off the seven-day concussion disabled list. ... Rockies RHP Tyler Chatwood (right elbow inflammation) is scheduled to throw 70 pitches Tuesday in a rehab start for Triple-A Colorado Springs. Barring a setback, Chatwood could rejoin the rotation Sunday and start against the Cincinnati Reds. ... Bochy said C Buster Posey probably would get a day off Tuesday. Posey started his eighth consecutive game Monday. ... Giants INF Tony Abreu (left knee bursitis) joined Triple-A Fresno and played five innings Monday, going 0-for-4. ... LHP Jeremy Affeldt (left groin strain) threw his second bullpen session Monday at the Giants' facility in Scottsdale, Ariz. ... San Francisco OF Andres Torres (left heel strain) traveled to Charlotte, N.C., to see Dr. Robert Anderson, the Carolina Panthers' orthopedist and a foot specialist, on Tuesday.