Astros 1, Padres 0: Lucas Harrell tossed a six-hitter and Matt Downs belted a solo home run as host Houston posted its fourth win in five games.

Harrell (7-6) limited San Diego to six singles and four walks while striking out seven. The 27-year-old became the first Astros pitcher to throw a complete-game shutout since J.A. Happ accomplished the feat in 2010.

The Padres made things interesting in the ninth inning. With two on and one out, Logan Forsythe hit a single to left fielder J.D. Martinez, who threw out Alexi Amarista at the plate. Harrell walked pinch hitter Mark Kotsay to load the bases, but struck out Nick Hundley to end the game and improve to 5-1 in seven home starts.

Downs provided all the offensive support Harrell needed with a leadoff homer in the third inning. Martinez had Houston's only other hit, a leadoff single in the second.

Clayton Richard (5-8) was superb for the Padres, allowing one run and two hits over seven innings. Richard, who struck out five without a walk, had his three-game winning streak snapped.

Forsythe and Yonder Alonso had two hits apiece for San Diego, which fell to 1-2 on its 10-game road trip.

GAME NOTEBOOK: Alonso started at first base for the first time since Saturday. He pinch-hit Tuesday after missing two contests with a sore left knee. ... Richard has allowed a total of two runs over 21 2/3 innings in his last three starts. ... San Diego's Chris Denorfia grounded out as a pinch hitter in the eighth inning, ending his career-best 12-game hitting streak. ... The Astros improved to 5-4 on their 10-game homestand.