Brandon Moss hit a grand slam in a five-run sixth inning, as Oakland finished off Houston thanks to a 13-1 decision in Thursday's rubber match of a three-game series.
Stephen Vogt hit a three-run double and Derek Norris added three hits, two runs scored and drove in a run for the Athletics, who have won fiver of their last seven overall.
Josh Reddick doubled twice, scored once and added an RBI, while Josh Donaldson went 2-for-3 and crossed home twice for Oakland.
Jeff Samardzija (2-1) scattered five hits and one run over eight innings, striking out six and failing to issue a walk.
Chris Carter's fourth-inning solo homer was the only meaningful offense for the Astros, who have dropped five of their last seven.
Scott Feldman (4-8) was tagged for nine hits and six runs along with five walks over 5 1/3 frames.