The Astros will enter the postseason as American League West champions after their 8-1 win over the Diamondbacks on Sunday claimed their sixth division title in seven seasons.
Houston clinched a playoff berth with Saturday's win in Phoenix, but did not control their own destiny for the division crown. They needed to beat the Diamondbacks and have Seattle beat Texas, just hours after they were eliminated from playoff contention.
Seattle did its part by beating Texas 1-0 behind a four-hit shutout by four pitchers, led by George Kirby's six innings, and the Astros took care of business grabbing a lead before an out was even recorded.
Jose Altuve started the game with a single on the game's first pitch and he scored on the very next pitch when Alex Bregman hit his 25th homer of the season.
The Astros scored four runs in the first inning, which was plenty for Cristian Javier, who allowed three hits over six scoreless innings for just his third quality start since the All-Star Break.
Bennett Sousa, Rafael Montero, and Hunter Brown closed it out for the Astros, with Montero allowing Arizona's lone run.
Kyle Tucker finished 2-for-4 with a triple and an RBI, giving him an AL best 112 for the season.
Jose Abreu collected two hits of his own, including his 18th homer.
The Astros will have five days off before starting their postseason run on Saturday when they host the Twins or Blue Jays in game one of the American League Division Series at Minute Maid Park as they try to become the first team since 2000 to repeat as World Series Champions.