HOUSTON -AP- Carlos Gomez had three RBI and finished a home run shy of the cycle and Luis Valbuena hit a tiebreaking two-run homer in the eighth inning to help the Houston Astros sweep the Seattle Mariners with a 9-8 victory Wednesday night.The game was tied at 7 with one on and one out when Valbuena launched a towering shot off Edwin Diaz (0-2) to the second deck in right field for his second straight game with a homer. Ken Giles (1-3) struck out two in a scoreless eighth for the win. Luke Gregerson allowed an RBI double to Robinson Cano with one out in the ninth before striking out Dae-Ho Lee with the bases loaded for his 14th save.Houston led by five runs early before Cano, Kyle Seager and Lee all homered in the fourth inning to cut the lead 5-4. The Astros stretched the lead to 7-4 with a two-run sixth before a three-run homer by Seth Smith tied it in the seventh.