Stassi homered off Padres right-hander Tyson Ross (1-1), snapping a scoreless tie in the process. Ross had cruised through his first four innings of work, retiring 12 of the 13 batters he faced before the fifth.

After allowing only an infield single to Derek Fisher with two outs in the third inning, Ross surrendered consecutive hits to Josh Reddick and Marwin Gonzalez to open the fifth. Ross rallied to record a groundball out with both Reddick and Gonzalez in scoring position, but erred in hanging a 2-1 slider that Stassi bashed into the Crawford Boxes in left field for a 3-0 lead.

An inning later, Reddick took Ross out of the park to right, as Houston reclaimed a three-run lead.

Ross allowed four runs on six hits with seven strikeouts over six innings.

Astros right-hander Charlie Morton (2-0) negotiated traffic in the second and fourth innings unscathed before allowing his first run of the season in the sixth when Chase Headley scored on Austin Hedges' fielder's choice. But that tally was unearned thanks to a fielding error, and Morton helped lower the collective ERA of the Houston rotation to 1.83 through three series.

Morton allowed four hits and three walks with seven strikeouts over six innings. Right-handers Will Harris, Joe Smith and Brad Peacock worked a scoreless inning each, with Peacock recording his first save with a perfect ninth inning.

Harris and Smith also faced the minimum, with Harris inducing a double play off the bat of Eric Hosmer to erase his leadoff walk to Carlos Asuaje.

The Padres (2-8) have yet to win a series this season.

-- Field Level Media