The Astros offense was lifeless getting runners on second a few times without pushing any runs across. The run for Houston came in the eighth inning well after the game was out of hand. George Springer dropped in a single to score Jason Castro from second.
The offense let down the starting pitcher again but Keuchel didn't help himself. Down 1-0, Kuechel walked Seth Smith to load the bases in the fifth inning. Back-to-back singles from Ketel Marte and Robinson Cano put the M's up 5-0.
Cano added a grand slam in the seventh off long reliever Michael Feliz to push the score to 9-0.
Catcher Eric Kratz was pressed into duty as a pitcher to save the over-taxed Astros bullpen in the eighth. A few singles and a wild pitch later and the Mariners added another two runs.
Dallas Keuchel's final line read: five earned runs on six hits, five strikeouts, two walks over six innings. Nathan Karns, who was 1-1 with a 5.28 ERA coming into Tuesday's game, pitching seven scoreless innings.
Astros record stands at 6-15, and the game is by far the low point of the season.