OAKLAND – Houston’s lineup comes at opponents with a procession of knives and swords and machetes, slashing and hacking until the pitcher begs for mercy. The Astros aim to destroy, and they usually do.

And when they fail, well, they suffocate teams into submission with an imposing starting rotation and gloves galore.

The A’s, however, spent the week squinting and shrugging at Goliath. They were so determined to foil the goal of a club built to win a World Series in October – and maybe two or three Octobers beyond – it wasn’t until Sunday that the Astros recovered from their bruises.

By the time Houston salvaged the last of four games with a 4-1 win at the Coliseum, it had received the message sent by the A’s: Oakland will not fall. It must be knocked down, hard and repeatedly.

Though winning three of four against the mighty Astros is -- by all accounts -- a generally satisfying achievement, utility man Chad Pinder needed a few moments to accept it with grace.

“I was not happy,” he told NBC Sports Bay Area. “I was really not happy. I took a little bit of time sitting at my locker.”

The source of Pinder’s temporary discontent was making the final out. His routine ground ball to shortstop meant the A’s were out of chances to do what they believe they are meant to do.

Win. No matter the opponent.

“Nobody wants to give away at-bats,” Pinder said. “Nobody wants to lose. So, when it comes down to the ninth inning, regardless of the score, guys aren’t giving away anything. When you see the guy in front of you not giving in, you don’t want to be the guy that makes the last out. You don’t want to be the guy that ends the game. You don’t want to be that guy.”

Yet winning three of four against a Houston team whose six highest-paid players combined make roughly the same amount as Oakland’s entire roster, is a huge net gain. It’s the order of the outcomes that left a residue of disappointment.

“Four-game sweeps are pretty tough, especially against a team like that,” manager Bob Melvin said. “But when you take the first three, you have some momentum and you want to take the fourth. We’re a little disappointed we couldn’t take the fourth game."

“But come tomorrow, when we look at three out of four, it’s a plus.”

The A’s under Melvin have made a habit of sticking their chins into the fight with baseball’s beasts. It’s as if coming into this series they ignored their 2-9 record against Houston this season – or maybe dismissed it because it’s mid-August, which is when the stakes start to rise.

The A’s (72-53) missed a chance to pull within 5.5 games of Houston (79-46) in the AL West but reminded themselves what it’s like to play games that matter. They left the ballpark 7.5 games behind the Astros but only one game behind Tampa Bay and two behind Cleveland in the Wild Card race.

They are making a spirited bid for October baseball despite the physical perils in their path. Starter Sean Manaea -- the ace of the staff a little more than a year ago -- has spent this season recovering from surgery. Jharel Cotton, a regular in the rotation when healthy, has endured two surgeries. Both pitchers in the midst of minor-league rehab assignments. First baseman Matt Olson underwent hand surgery and missed the first six weeks of the season. 

The team’s main offseason trade acquisition, second baseman Jurickson Profar, has been abysmal, toting the lowest batting average (.204) and on-base percentage (.269) of any regular in either league.

These shortcomings have had little impact on the A’s. Matt Chapman and Matt Olson keep crushing, offsetting Khris Davis’ relatively quiet bat. The pitching and defense have been solid, but the spirit keeps this bunch ticking.

The A’s believe, and keep believing, until the final out. Their nine walk-off wins are second only to the Dodgers’ 10. Since opening the season with a 15-21 record, Oakland is 56-32. 

“They’re fighters,” Melvin said of the A’s. “The Pinders and the Chapmans and the Olsons, these guys won all the way up (through the minors). They have an expectation to win all the time.”

As much criticism as the Coliseum gets, and most of it is deserved, the A’s 40-24 home record is behind only the Yankees (49-19) and Astros (43-15) in the AL. Still, upon arriving at the ballpark Sunday, the plan was to leave with a 41-23 home record.

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“Obviously, you want to sweep,” Pinder said. “But the first thing we did (in the clubhouse) was put on the music. We had a good series, and you really want to win the series. We did, so we’ll take it.”

Particularly against a team that has kneecapped the A’s more than a few times. The pursuit continues.