DENVER -- Juan Nicasio has figured out how to beat teams with his arm. He also showed he can do it with his bat.
Buster Posey singled and reached base for the 49th straight game against Colorado.
Nicasio (8-6) struggled with his location early this season and was sent to Triple-A on June 28 to work on his command. He is 3-2 since rejoining the Rockies on July 12 but has pitched deeper into games.
"It's a hard slider that he's throwing that he's getting swings and misses," manager Walt Weiss said. "When he gets it near the plate, it's been effective. Early on, a lot of those sliders were a ball out of his hand and didn't really serve a purpose."
The Giants struggled against the righty, managing just four hits. Two came in the first inning when they loaded the bases before Nicasio struck out Pablo Sandoval to end the threat.
"First inning, bases loaded and no runs, I was feeling happy," Nicasio said.
Giants starter Barry Zito didn't share the feeling.
The Rockies began a nine-game, 10-day homestand with a strong performance against Zito (4-10), who has struggled away from home this season. His numbers didn't improve in his short outing at Coors Field.
Zito allowed five runs and nine hits and struck out one in four innings in his second start since being put back into the rotation. He is 0-8 with a 9.61 ERA on the road this season.
"I don't know about tonight," he said. "I thought I had good command."
He worked out of trouble in the first inning before the Rockies got to him in the second.
Nolan Arenado led off with a bloop single -- one of his three hits -- and Helton crushed a 1-1 curveball into the Rockies' bullpen to give Colorado a 2-0 lead. It was Helton's ninth homer of the season and the 363rd of his 17-year career.
Blackmon, who entered the game in the second inning for Dexter Fowler, led off the third with his fourth homer to give the Rockies a 3-0 lead. Colorado tacked on two more runs in the fourth on a bases-loaded single by Nicasio and a groundout by Blackmon.
"I looked the film on the home runs. Buster had his glove on the ground, and that's where the pitches were on the home runs," Zito said. "I wanted the curveballs down and away, and that's where they were."
The Giants got a scare when right fielder Hunter Pence crashed into the wall trying to track down Michael Cuddyer's triple in the first inning. Pence lay on the warning track before San Francisco's trainers came out to tend to him. After a brief examination, he stayed in the game.
"He hit the wall pretty good, I mean really good," manager Bruce Bochy said. "He got the wind knocked out of him. Once he got his wind back, he was all right. I'm sure he will be ready to go."
Pence and the Giants couldn't do much against Nicasio, who tied a season high with nine strikeouts. He finished his night by striking out Brandon Crawford with runners on first and third to end the sixth.
"He's come a long way minimizing damage," Weiss said. "The big one was the sixth inning. We really wanted him to get through the sixth without having to go to the pen. Our guys were pretty taxed so we didn't want to go there that early, so that was big for Juan to get through that sixth inning."
Rockies right-hander Rafael Betancourt has a torn elbow ligament, the closer said Monday night. Betancourt said he will have platelet-rich plasma therapy instead of Tommy John surgery in the hope of returning sooner. ... Fowler left with a left lateral knee bruise. He is day to day. ... The outfield sprinklers came on briefly while the Giants were in the field in the fourth inning. ... Colorado SS Troy Tulowitzki (sore oblique) sat out his second straight game. He is expected to be back in the lineup Tuesday. ... Rockies RHP Tyler Chatwood (elbow) will make a rehab start with Triple-A Colorado Springs on Tuesday. He is scheduled to throw 75 pitches and could be back in the rotation this weekend. ... Giants LHP Jeremy Affeldt (left groin strain) threw a bullpen session in Arizona on Monday. He next will go on a rehab assignment. ... San Francisco OF Andres Torres (left Achilles strain) flew to North Carolina to see a specialist. ... Giants RHP Yusmeiro Petit (0-0) will face Colorado RHP Chad Bettis (0-2) on Tuesday night.