Pirates 5, Astros 4: Travis Snider scored on a dropped pop fly with two outs in the bottom of the ninth as host Pittsburgh recorded a comeback victory over stumbling Houston.

With the bases loaded, Russell Martin lifted a 3-2 offering from Edgar Gonzalez (0-1) into shallow right field, where right fielder Jimmy Paredes and second baseman Jake Elmore converged. The two bumped and the ball fell to the turf, allowing Snider to score the winning run as the Pirates backed into their fourth straight victory. Paredes was charged with the error.

Pedro Alvarez hit a 462-foot two-run homer in the bottom of the eighth to pull Pittsburgh, which once trailed 4-1, into a 4-4 tie. Andrew McCutchen homered, doubled and singled to improve to 29-for-63 against American League teams.

The game-winning rally made a winner of Justin Wilson (4-0), who threw a scoreless top of the ninth to finish 4 1/3 scoreless innings for the Pirates bullpen. Garrett Jones had an RBI double in the sixth to pull Pittsburgh within 4-2.

The Astros took a 4-1 lead in the fifth on a Matt Dominguez solo homer, an Elmore RBI single and a pair of Pirates throwing errors on a stolen-base attempt that allowed Robbie Grossman to score from third. Grossman doubled, walked and scored twice for Houston, which has lost seven of its last eight..

GAME NOTEBOOK: Alvarez's homer was the 10th-longest in PNC Park history. ... The Pirates placed RHP Jose Contreras on the bereavement list and recalled RHP Jared Hughes from Triple-A Indianapolis. ... Astros starter Jordan Lyles allowed two runs (one earned) in five innings. Starter Jeanmar Gomez gave up four runs (three earned) in 4 2/3 frames for Pittsburgh.