San Francisco took a quick 2-0 lead after the first inning, thanks to a two-run home run by Buster Posey. The Giants would tack on another two runs in the second inning, on a Joaquin Arias RBI single, and a Justin Christian RBI ground out, giving the Giants a 4-0 lead.
As it turns out, Posey's homer was all Bumgarner really needed.
Bumgarner pitched seven strong innings, giving up just one run on two hits, while walking two and striking out five en route to his 11th win of the season.
Javier Lopez, Sergio Romo and Santiago Casilla all held Houston's offense in check, while preserving the lead for Bumgarner.
Wandy Rodriguez fell to 7-7 on the year, picking up the loss. Rodriguez allowed four runs on seven hits and two walks in six innings, while striking out four.
Houston's lone run was scored on a Chris Snyder home run, one of just three hits for Houston on the night.