OAKLAND -- Matt Chapman heard the footsteps entering Thursday night’s game.

Though the A’s began the day in sole possession of first place in the American League West for the 17th consecutive day, Chapman admitted before the game he was “guilty” of scoreboard watching and well aware of the surging second-place Astros, who had won their eighth game in a row just a few hours earlier. So, he took it upon himself to make sure Oakland kept pace, smashing two home runs in a 5-1 victory over Arizona at the Coliseum. The A’s remain atop the AL West by 2 1/2 games and hold the best record in the AL at 18-8.

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The two Matts -- Chapman and Olson -- powered the entirety of Oakland’s offensive production by driving in all five runs on a trio of homers.

“They’re hitting in the lineup in spots you expect production, so it doesn’t surprise you,” A’s manager Bob Melvin said. “They’re cornerstones for our team and have been for a while now, whether it’s offense or defense. A lot of our confidence comes from those guys, and when they have good nights, we feel doubly good.”

It was the second time Chapman and Olson have both homered in a game this season and the 16th time in their careers. They had each gone deep once through the first four innings, providing an extra jolt of energy to A’s starter Sean Manaea, who tossed 5 1/3 innings of one-run ball to earn his first win of the season.

“Them hitting bombs is huge,” Manaea said. “It’s just fun to watch. Those two balls that Chapman crushed, just hearing it off the bat had a different sound. When they do something like that, it’s crazy.”

Chapman’s first home run, a solo shot, came in the first inning off Arizona starter Alex Young to provide the A’s an early lead they never relinquished. His second homer was a two-run shot in the eighth off Yoan López. Both were no-doubters, as each left the bat at 110 mph and traveled at least 428 feet, per Statcast.

“I don’t know that I’ve ever seen two balls go way up in the upper deck in left field like that,” Melvin said. “Two balls to go way up there does not happen. He got a good piece of both of them.”

Not even Chapman could believe that his first homer ended up in the second deck of the Coliseum, territory that has usually been reserved for only the game’s elite sluggers over the years.

“I kind of surprised myself there. I don’t know if I’ve hit a ball like that since the Minor Leagues,” Chapman said. “It felt good to be able to drive a few balls today while not trying too hard. Credit to the guys who got on base ahead of me. To bounce back after dropping the first two [in Arizona] was big for us.”

Olson’s two-run blast came in the fourth off Young, and it was his team-leading ninth homer of the season. Right behind Olson? Chapman, with eight.

“It seems like every time I hit one, Olson hits one and one-ups me,” Chapman said. “We always joke that we usually don’t hit them on the same days. But when we do, it’s a lot of fun.”

During a video call with reporters before Thursday’s contest, Chapman mentioned an adjustment at the plate he was making in order to give himself more time to decide whether he wants to move his swing to the baseball or take a pitch. That mechanical tweak worked well, as the third baseman notched his sixth career multi-homer game and his second of the season.

“That was my main focus all night. Trying to be on time,” Chapman said. “It’s funny how when you try to focus on making that little adjustment, good things happen. I felt a lot more comfortable and was able to catch the ball out in front a little more.”

Manaea continued to trend in the right direction after a rough start to his season by turning in his longest outing of the year. The left-hander limited the D-backs to one run on five hits, striking out four batters over 5 1/3 innings. The A’s bullpen was nearly flawless in relief of Manaea, closing out the game with 3 2/3 scoreless innings and allowing only one hit.

On a night when his fastball was topping out at 89 mph, Manaea finally found a good grasp for his changeup. The pitch has been devastating for opposing hitters over his career when it’s working, and it looked sharp. Manaea threw it for 20 of his 74 pitches, generating 10 swinging strikes and three called strikes.

“He kept the ball down and on the ground. Pitched in just enough to open up away and threw some good changeups,” Melvin said. “His velo wasn’t great today, but if you keep the ball down and have late movement, you’re going to be successful. Good pitchers find a way to use what they have on a particular night to get outs. That’s what he did.”