The NL West-leading Giants had managed just six combined runs over their previous three games before exploding for a season-high 16 runs in Friday's series opener. They have now scored four or more runs in nine straight games at Coors Field.
"Hopefully that gives them confidence and gets them relaxed a little bit," Giants manager Bruce Bochy said of his team's offensive outbursts. "
On Saturday, Posey hit a two-run homer in the first and added a run-scoring single during a four-run eighth. Angel Pagan added a ninth-inning solo shot and drove in three while Melky Cabrera also homered for San Francisco, which will look for the sweep of this three-game set on Sunday.
Madison Bumgarner (12-6) got the win, allowing one run on five hits with a walk and seven strikeouts over six innings. He improved to 5-5 on the road this season, compared to 7-1 at home.
Josh Rutledge hit a solo homer and Matt McBride, who was called up earlier Saturday, went 2-for-4 with an RBI double for the Rockies, losers in seven of their last eight games.
"We're not disappointed with six runs and 14 hits and a lot of young kids out there on the field," Colorado manager Jim Tracy said of his team.
Jeff Francis (3-4) had won four of his previous five starts against San Francisco but lasted just 3 2/3 innings, giving up six runs on nine hits in the setback.
Posey leads the National League with 25 RBI since the All-Star break. His two- out, first-inning blast to left scored Cabrera, who added a solo shot in the third -- his 11th homer of the year -- and later worked a bases-loaded walk in the fourth.
Joaquin Arias and Pagan added RBI singles during that frame, which saw the Giants take a commanding 6-0 lead.
Rutledge hit a one-out solo shot in the sixth and McBride doubled home Ramon Hernandez an inning later before scoring on Jonathan Herrera's single, making it 6-3.
The Giants, though, extended their advantage in the eighth, which began with Brandon Belt's double. Pagan followed with an RBI single, advanced to second on a throwing error by Wilin Rosario and stole third before coming home on Ryan Theriot's Tobago. Posey later plated Theriot with a single and Gregor Blanco capped the frame with a pinch-hit sac fly.
In the bottom half, Dexter Fowler scored on Sergio Romo's wild pitch before Hernandez doubled home Carlos Gonzalez.
Pinch-hitter DJ LeMahieu sealed the final result with an RBI single in the home ninth.
Posey has 16 homers on the season and six since the All-Star break...Fourteen of the Giants' 17 multi-home run games this season have come on the road...Earlier Saturday, the Rockies placed outfielder Michael Cuddyer and pitcher Christian Friedrich on the 15-day disabled list, selected the contract of McBride from Triple-A Colorado Springs and recalled pitcher Edgmer Escalona from the same club.
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