Houston, TX - Jake Marisnick's three-run blast was the last of five Houston home runs, fueling a 10-1 takedown of playoff-hopeful Seattle in the second of three between the clubs.
Chris Carter and Alex Presley each hit a two-run shot in the first, with Matt Dominguez and Carlos Corporan added solo homers for the Astros, who dropped a 10-5 decision in Friday's opener.
Dexter Fowler finished 3-for-3 with two runs scored and Dallas Keuchel (12-9) scattered a run on seven hits with eight strikeouts over eight solid innings.
Robinson Cano drove in the lone run for the Mariners. Chris Young (12-9) was pulled in the fourth, having surrendered eight hits and seven runs -- including four of Houston's longballs.
Seattle remained a game back of Oakland for the AL's first wild card slot, as the A's lost at home to the Phillies.