Miley pitched six strong innings and the Astros backed him up with a season-high six homers to rout the Seattle Mariners 10-2 Friday.
"He had to pitch so differently tonight than he normally does," manager AJ Hinch said. "He didn't have his cutter at all so he was pitching with one weapon down and really his best weapon ... because he didn't have a feel for it. A good night on a night where he didn't pitch like himself and didn't use his stuff like he normally does."
Miley (10-4) allowed three hits and two runs to win his third straight decision.
Yordan Alvarez, Jake Marisnick, Martin Maldonado and Jose Altuve all connected off starter Yusei Kikuchi (4-8) to leave him tied with Justin Verlander for most home runs allowed in the majors this season at 28.
Carlos Correa and Aledmys Diaz also homered for Houston, which improved to 10-1 against the Mariners this season.
It was the most home runs that the Astros have hit in a game since also going deep six times in a 17-6 victory over the Twins on May 31, 2017.
"That was a pretty explosive night obviously and we did a good job of really producing throughout the order," Hinch said.
The four home runs Kikuchi gave up were a season high and he allowed nine hits for the second time in three starts to lose his third consecutive decision and give Houston three starters with 10 or more wins this season.
Daniel Vogelbach hit a two-run homer for the Mariners, who lost their second straight after winning their previous six games.
Houston got things going when Alvarez sent the second pitch of the second inning into center field for his 13th homer. There was one on and two outs in the inning when Marisnick put one on the train tracks atop left field to make it 3-0.
Maldonado made it 4-0 when he homered into the seats in right field in his second game with the Astros since a trade from the Cubs on Wednesday. George Springer tripled with two outs in the inning and Altuve extended the lead to 6-0 with his shot to left field.
"He had a hard time getting the swing and miss," manager Scott Servais said of Kikuchi. "They weren't really biting on the slider tonight. They were on the fastball. They've got a good lineup and it's a deep lineup and you've got to make pitches. You've got to keep commanding the fastball and he didn't really have a good command."
Reggie McClain, who was recalled from Triple-A Tacoma before the game, took over for Kikuchi to start the fifth in his major league debut. He walked Alvarez with one out before Correa hit his third home run since coming off the injured list a week ago to make it 8-0.
Five pitches later Diaz also went deep, putting one in the seats in left field to push it to 9-0.
Miley walked three Mariners early, but didn't allow a hit until Tom Murphy legged out a single on an infield grounder with one out in the fifth. He walked Mallex Smith with one out in the inning, but retired J.P. Crawford to end the threat.
Domingo Santana walked with one out in the sixth and Seattle cut the lead to 9-2 when Vogelbach hit his 26th homer.
Mariners: Servais said INF Ryon Healy, who is on the 60-day injured list with spinal stenosis, will have season-ending hip surgery. ... RHP Felix Hernandez, who has been out since May 12 with a strained right shoulder, pitched two perfect innings in a rehabilitation start for the short-season Class A Everett AquaSox on Friday. He struck out two and threw 20 pitches.
Astros: C Robinson Chirinos was scratched from the lineup because of a sore left shoulder. ... RHP Ryan Pressly (right knee soreness) played catch on Friday and will throw what manager Hinch called a "pretty extensive bullpen" on Sunday. He isn't sure when he'll return but said it would not be in this series or the next one which is Tuesday and Wednesday against Denver.
WELCOME TO HOUSTON
The Astros introduced Zack Greinke on Friday after the ace was acquired from Arizona in a surprising trade on Wednesday. Greinke was 10-4 with a 2.90 ERA in 23 starts this season for the Diamondbacks and provides an immediate boost to a rotation led by Verlander and Gerrit Cole.
Greinke is expected to make his Houston debut on Tuesday against the Rockies.
The 2009 AL Cy Young Award winner has also played with Kansas City, Milwaukee, the Angels and Dodgers in a 16-year career.
"Happy to be here in Houston," he said. "It's a pretty darn good team, maybe the best team I've played with. I've been on some good teams and there's a good chance this is the most talented team I've been on."
Mariners: LHP Marco Gonzales (12-8, 4.21 ERA) is scheduled to start for Seattle on Saturday night. Gonzales allowed six hits and one run in seven innings of an 8-1 win over the Tigers in his last start.
Astros: RHP Aaron Sanchez (3-14, 6.07) will make his debut in Houston on Saturday after being traded from Toronto on Wednesday. Sanchez has lost 13 consecutive decisions to lead the majors in losses, but struck out 10 in his last start and did not factor in the decision in Toronto's 5-1 loss to the White Sox.
More AP MLB: https://apnews.com/MLB and https://twitter.com/AP-Sports
Astros tattoo M's for 6 homers
The Astros score nine runs on six home runs, including Jose Altuve's 17th, in a rout of the Mariners.