OAKLAND, Calif. — They came out on a cool California day, while seagulls soared overhead and the Astros absorbed an atypical showing from such a reliable set of relievers.

They’re pesky and predicated upon pressure, a departure from the detonating bats for which this team is renowned. Forty-three of the Astros’ 95 home runs are on the injured list and none of them are near a return.

Boomers are hurt. Burners are here.

“I think,” Alex Bregman said, “we switched from a team that hits the ball out of the ballpark to a team who runs, goes first to third and steals bags overnight.”

Meet the June Astros.

Speedy nine-hole hitter Myles Straw stole three bases, collected three hits and scored three times, including the go-ahead run in the Astros’ 6-4, 12-inning win over the A’s on Sunday.

For only the 13th time in 60 games, the Astros did not hit a home run. They collected two extra-base hits and, yet, concluded a sweep of their division rivals while deploying a makeshift lineup learning its new way to win.

Astros insider: Takeaways from series at Athletics

Manager A.J. Hinch’s group hit and ran, started runners at will and advanced 90 feet with a havoc-harboring mindset. In the fifth, they scored two runs on a ball that did not leave the infield.

Straw scored three times from second base on a single — all after the nine-hole hitter stole the base to start the rally.

“We know we can score, we know we can put pressure on teams,” Hinch said. “We’re doing it a little differently than we’re accustomed to just because of the speed we can put in the lineup. But guys are into it. And they’re doing a good job of playing the game.”

Hitting behind Tony Kemp and in front of Derek Fisher, two fast men in their own right, Straw had three singles. His leadoff knock in the 12th inning against A’s reliever Lou Trivino allowed him aboard for a fourth time in as many plate appearances.

Straw crouched into a secondary lead with the green light to steal. The 24-year-old rookie always has it.

Always?

“Always,” Straw said.

While Fisher battled Trivino, Straw took off. Catcher Josh Phegley did not throw. Straw’s third steal put him within one of tying the club’s single-game franchise record.

He did not break it. Winning the game must suffice. Michael Brantley, hitless in his first five at-bats, blistered a single to right field. Straw scored without issue.

In the fifth inning,while the team trailed by a run, eight-hole hitter Kemp coaxed a leadoff walk. Straw saw six pitches and filled the count. Hinch started Kemp on the seventh. The nine-hole hitter bounced it through the left side, a pleasing piece of hitting to execute a hit-and-run and place runners at the corners.

“I’m doing everything I can to just let those guys behind me take care of the rest,” Straw said. “Getting on base is my job and wreaking havoc on the bases.”

He stole second again and scored on Bregman’s infield single Jurickson Profar threw errant. The baseball did not bounce far from Matt Olson at first, just two or three feet from his glove. Straw slid into third, bounced up and sprinted home.

There was no throw. Straw slid safely, both hands extended for the headfirst presentation.

“He had a very impactful game, obviously,” Hinch said. “The pressure he can put on an opponent, you can feel every time he’s coming up to bat or every time he got on base. To see him fly around the bases is huge. Exactly the reason we like him and we think he can help a winning team is because of the pressure he puts on.”

Yuli Gurriel drove in two runs, too, including a 12th-inning single to afford insurance in a game the bullpen nearly blew.

Solo home runs in the seventh and eighth innings erased the two-run advantage with which the Astros entered the final frames. Ramon Laureano launched one against Will Harris, ending the righthander’s 11-appearance scoreless streak.

Matt Chapman crushed one to begin the eighth off Ryan Pressly, tying the game. Preceding this performance, Pressly pitched 50 times as an Astro. Never, until now, had he allowed three or more hits. It was only 10 days ago that he allowed his first earned run of the season.

He began his Sunday stint with three four-seam fastballs. Two evened the count to Chapman. A third left the ballpark to center field.

Khris Davis and Robbie Grossman deposited singles, sending Laureano to the plate. He fouled five two-strike pitches, pushing Pressly near 30 pitches. A curveball caught the inside corner and ended the battle after 11 pitches. Pressly pranced from the field with the game in hand.

“He never caved,” Hinch said. “We don’t see that happen very often, but Chapman is really good. When he gives up the run, you’re trying to get to the end of the inning. When he has to make big pitches, he still steps up and does his job.”

Astros starter Gerrit Cole completed six strenuous innings. He elicited only 10 swings and misses and endured 29 foul balls. The four strikeouts Cole collected were his fewest of the season.

Still, two solo home runs in the second inning were all the A’s mustered against the flamethrowing righthander. He retired 12 of the final 14 hitters he faced.

chandler.rome@chron.com

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