Yordan Alvarez homered and drove in four runs to pace a Houston offensive onslaught as the Astros bashed four home runs and rolled to a 12-3 win over the visiting Seattle Mariners on Friday.

Alvarez (2-for-5) was one of five Astros with a multi-hit game as Houston scored at least two runs in each of the first five innings. Seven starters drove in at least one run as Houston pounded out 15 hits, eight for extra bases, to secure the opener of a three-game series.

The Astros wasted no time jumping on Mariners left-hander Yusei Kikuchi (7-7), as Alvarez followed an RBI triple by Carlos Correa with a run-scoring groundout for a 2-0 advantage.

Jake Meyers doubled the lead with his third home run, a two-run shot to center field in the second inning that drove home Chas McCormick.

The Astros continued the power display an inning later when Alvarez and Yuli Gurriel smacked back-to-back home runs. Alvarez cranked his 23rd homer 429 feet to center, driving in Correa (2-for-3, three runs) for a 6-0 lead. Gurriel followed with his 13th homer, a 401-foot blast to left-center.

Four batters later, Kikuchi was gone.

Kikuchi continued his recent struggles, allowing seven runs on seven hits and three walks while recording just eight outs. He is 1-4 with a 6.69 ERA over his past eight starts.

Astros right-hander Lance McCullers Jr. (10-4) was the beneficiary of the run support. He retired the first 11 batters he faced before surrendering a solo homer to Mariners third baseman Kyle Seager, his 28th, with two outs in the fourth inning.

McCullers ran into more two-out trouble in the sixth, yielding three successive base hits, including an RBI single by Abraham Toro, before inducing an inning-ending grounder.

McCullers allowed two runs on five hits and one walk with eight strikeouts over six innings.

Martin Maldonado also homered for the Astros, producing his ninth of the season off Mariners reliever Erik Swanson leading off the fifth inning. Jose Altuve followed with his first triple of the season and scored on Michael Brantley's groundout.

--Field Level Media