Christian Walker stroked a two-run, two-out single to left field in the 10th inning as the visiting Arizona Diamondbacks outlasted the Houston Astros 5-2 on Wednesday.

Shortly after Daulton Varsho bounced into the go-ahead fielder's choice, Walker plated Varsho and Jake McCarthy with his hit off Astros reliever Bryan Abreu. McCarthy reached on the second infield single of the 10th for Arizona (72-84), which denied the Astros (102-54) a shot at clinching home-field advantage in the American League postseason.

Will Smith (0-3) took the loss for Houston. Mark Melancon earned his 18th save for Arizona by retiring the side in order in the bottom of the 10th.

Arizona starter Zac Gallen and his counterpart, Houston's Justin Verlander, were outstanding and confirmed their status as Cy Young Award candidates in their respective leagues.

Gallen faced the minimum through four innings. He retired the first two batters in the fifth before suddenly finding trouble, surrendering a double to Trey Mancini and then a game-tying, two-run homer to Chas McCormick, whose 14th long ball carried out to right-center.

Gallen wound up completing seven innings. He surrendered two runs on six hits and one walk with six strikeouts while tossing 104 pitches, 70 for strikes.

Verlander minimized the damage in a strange first inning that featured two infield hits and a passed ball on catcher Martin Maldonado.

Varsho led off the game with a double to right-center, went to third on Pavin Smith's single to short and came home on the passed ball. Smith scored on Walker's sacrifice fly after moving to third when McCarthy nipped Verlander at the bag for a bunt single.

Verlander held the line there, working around his throwing error and a subsequent wild pitch that placed Geraldo Perdomo at third base with two outs in the second. He escaped several other jams, including runners at the corners with no outs in the seventh.

Verlander induced a pair of infield popouts before rearing back and striking out Smith on a 97 mph fastball on his 101st and final pitch. He allowed two runs (one earned) on six hits and one walk with eight strikeouts in seven innings, lowering his major-league-leading ERA to 1.80.

--Field Level Media