HOUSTON -- They only had one win to show for it, but the Mariners had played the Astros tough in their first 10 meetings this season. Three extra-inning losses, six games decided by one or two runs, a run differential of just minus-10 despite the lopsided win-loss record.

But even that storyline went out the window on Friday as the Astros bashed six home runs en route to a 10-2 win in the series opener at Minute Maid Park, with Mariners starter Yusei Kikuchi surrendering four of the long balls as his rough rookie campaign continued.

• Box score

Kikuchi, the Mariners’ prized offseason free-agent acquisition, fell to 4-8 with a 5.49 ERA in 23 starts while allowing nine hits and six runs in four innings. Since starting the season 3-1 with a 3.43 ERA in his first 11 outings, the 28-year-old from Japan has gone 1-7 with a 7.65 ERA in his past 12 starts.

The four home runs allowed pushed Kikuchi’s season total to 28, tied with Astros ace Justin Verlander for the most allowed in the Majors.

“It’s not really the level of play, but the style of play that’s different,” Kikuchi said of the transition from Japan. “The power is definitely bigger over here. Today, the home runs were not only solo home runs, but two-run home runs, as well. If I can limit those, it will help me moving forward.”

Kikuchi had trouble getting ahead in counts and the Astros made him pay, jumping on three 1-0 pitches for home runs when he tried to come back in the zone. Lack of command combined with a tough park to pitch in made for a lethal combination.

Four of the Astros’ home runs on the night were 368 feet or less, according to Statcast, but they all counted.

“Certainly, the command was not there tonight,” Mariners manager Scott Servais said. “And in this ballpark, they’re at full strength right now. So you have to make pitches, you have to locate. He had a hard time getting them to swing and miss.”

Kikuchi normally counters his low 90s fastball with a tough slider, but that combo wasn’t working against the patient Astros.

“They laid off his slider tonight, and that’s kind of his pitch, getting them to bite on that and widen the strike zone or get them to go after it,” Servais said. “And they did not offer at it when it was out of the zone. They got after a couple that were in the zone. It’s a really big pitch for him. So when you’re not locating the fastball and they’re not biting on your secondary pitch out of the zone, it can be a tough night.”

Mariners catcher Tom Murphy acknowledged the Astros’ approach made it rough on his starter.

“This team doesn’t chase. They’re going to make you throw the ball in the strike zone,” Murphy said. “If you don’t show them you can throw strike one, they’re going to get deep into counts and get the pitch they want to hit.”

Houston added two more long balls off rookie reliever Reggie McClain, who made his MLB debut in the fifth, to reach their season high for the season. Six different Astros homered, though none of those came from three of Houston’s primary power hitters -- George Springer, Michael Brantley or Alex Bregman.

Seattle countered with a two-run pop by Daniel Vogelbach in the sixth, his 26th homer of the season, but that was all the Mariners managed as they fell to 47-65. The Astros have won 21 of their past 29 games and lead the American League West at 71-40.

Right-hander Zac Grotz joined McClain in making his MLB debut, pitching a scoreless seventh inning before giving up the game’s final run in the eighth. The two rookies were promoted after Seattle dealt three pitchers at Wednesday’s Trade Deadline. The Mariners have now tied their franchise record by using 61 different players in a season with nearly two months still to go.

Seattle has used the most players (61), pitchers (39) and relievers (34) of any team in the Majors this season.