Jason Heyward delivered a go-ahead two-run homer and the Houston Astros clinched their fourth straight American League West title with a 4-3 win over the visiting Seattle Mariners on Tuesday.

Josh Hader notched a four-out save for Houston, which overcame a dismal start to the season to capture its seventh division crown in the past eight years. The Astros (86-72) were 12 games below .500 on May 8 and sat 10 games behind Seattle for the division lead on June 18.

Houston will host a best-of-three AL wild-card series next week.

The Mariners (81-77) fell 2 1/2 games back of the final wild-card spot with four games remaining.

Heyward put the Astros up 4-3 with a two-run homer in the fifth off Seattle starter Logan Gilbert. It was Heyward's second homer in as many games as the veteran fills in for injured slugger Yordan Alvarez, who is out the series due to a bruised right knee.

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Hader entered with two outs in the eighth and struck out J.P. Crawford with runners on the corners to end the inning. The left-hander pitched a perfect ninth, fanning Julio Rodriguez to start Houston's latest division-title celebration.

Alex Bregman and Kyle Tucker also homered for the Astros, who got 5 2/3 innings from starter Framber Valdez (15-7). The left-hander allowed three runs on eight hits and two walks while striking out four. He exited with runners on second and third before Bryan Abreu retired Luke Raley to keep Houston ahead 4-3.

Abreu pitched a perfect seventh before Ryan Pressly ran into trouble in the eighth. Pressly issued a walk to Justin Turner, allowed a single to Jorge Polanco and threw a wild pitch to put runners on the corners with one out. He retired Mitch Garver on a shallow fly before Hader took over.

Gilbert (8-12) surrendered four runs on five hits, including three home runs, with one walk and six strikeouts over six innings.

Bregman opened the scoring with a two-out solo shot in the bottom of the first. Polanco responded with a long ball leading off the second to pull Seattle even at 1-1.

Rodriguez and Cal Raleigh singled to start the Mariners' third before Randy Arozarena stroked an RBI double. Polanco made it 3-1 two batters later when he singled home Raleigh.

Tucker pulled Houston within 3-2 on his homer to begin the bottom of the fourth.