With one swing of the bat in the first inning — on the first pitch of the game — Brad Miller got the Mariners’ offense revving back up with a line-drive single.

With another swing of the bat in the sixth, Miller knocked another “first” off his to-do list — first major-league homer, a no-doubter off Bud Norris.

“He threw one in there and it felt pretty good; it felt really good,’’ Miller said. “It felt pure. And I kind of blacked out there for a little bit.”

He revived himself, and with another swing in the eighth, well, now Miller was just piling on to his breakout game. He launched a three-run homer that put a bow on the Mariners’ 10-7 victory over the Houston Astros at Minute Maid Park.

They’ve won four in a row, and have been putting up the sort of offensive prowess not seen from this ballclub in quite awhile. As much as the four home runs — Kyle Seager and Justin Smoak joined Miller — manager Eric Wedge was as pleased with the eight walks the Mariners drew, and the quality of their at-bats as they picked right up where they left off before the All-Star break.

“You look at the at-bats, the length of the at-bats, they’re real, they’re productive,’’ Wedge said. “Even if one guy doesn’t get it done, he’s putting up hard-fought at-bats, and that’s going to benefit the next guy. That’s what good hitting clubs do, and we’ve been doing it for a little while.”

That was exemplified by Mike Zunino, the only Mariners starter not to get a hit – but he walked three times.

“Everybody is just piecing good at-bats together, honestly, not trying to do too much,’’ Miller said. “I don’t know why but hitting is contagious. Guys have good at-bats, even if they don’t get a hit necessarily and they hit a ball hard or make a loud out, it just sets the tone. The next guy up there has a little more confidence.”

Seager’s homer in the fourth extended his hitting streak to 15 games, longest current streak in the majors. It also gave the Mariners homers in 23 consecutive games, just four off the major-league record of the Rangers in 2002.