OAKLAND -- Behind the neat, clean storylines of the A’s 4-2 Interleague victory over the Cardinals on Sunday afternoon at the Coliseum was the harsh reality of unstinting effort, as delivered by Tanner Roark and Dustin Garneau.

Obtained from Cincinnati at Wednesday’s Trade Deadline, Roark spun the classic tale of the successful debut, allowing one run and four hits in five innings. Garneau, claimed off waivers from the Angels on Saturday, threw in a dash of the heartwarming homecoming story, harkening to the 19 games he played with Oakland in 2017. He contributed the A's biggest hit of the afternoon, a two-run fourth-inning double. And since they were not only batterymates but also recent acquisitions, they lent a symmetry to the result, which hiked Oakland’s record to a season-high 16 games above .500 (64-48).

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Everything fit together nicely for the A’s. But the protagonists, Roark and Garneau, worked hard to gain each advantage, big or small, against the Cards’ formidable lineup.

“No inning was easy,” Roark said. “It was a constant grinder from pitch one. I just wanted to look at the glove and throw the ball to it. And whatever else happens, happens.”

The most significant happening of all was the third inning, when Roark blanked St. Louis despite laboring through 35 pitches.

“Just the way we drew it up,” Roark said.

Actually, Roark’s remark wasn’t completely sarcastic. He and Garneau, who were virtually strangers a few days ago (“I faced him before,” Garneau said), spent much of Saturday discussing their game plan, a required stage of the pitcher-catcher courtship.

“It’s a dance, pretty much,” Garneau said. “The more you can get on tempo, you just kind of let him lead.”

But Roark and Garneau did not plan for Paul Goldschmidt’s 14-pitch plate appearance that ended with a walk that loaded the bases with two outs.

Goldschmidt, who struck out in the first inning, nearly did so again. He drew his free pass after fouling off eight consecutive 3-2 pitches.

Roark recovered by striking out Marcell Ozuna. To throw that many pitches and still spin a scoreless inning, he said, required him to steady himself -- not only physically, with his pitching mechanics, but also psychologically, with his outward demeanor.

“You’ve got to know you still have to execute and not try to be fine,” said Roark, who walked two and struck out six. “You still have to be competitive. The hitter’s got to know that nothing is wrong, like it’s the first pitch of the first inning. Body language and stuff. You’ve got to have no emotion. You can’t give in. Once you give in, that’s when you get beat. And I don’t want anybody in the box to think they’re better than me.”

That statement reflected the reputation that Roark, a seven-year veteran, brought to Oakland. The A’s heard much about Roark’s determination after his acquisition was announced.

This remark from former big league closer Jeff Brantley, who is now a Reds broadcaster, was typical: “Tanner is an absolute champ and a phenomenal competitor. I’d take five of him in my rotation.”

Roark proved to Oakland manager Bob Melvin that the hype was worth believing.

“He’s a bulldog,” Melvin said of Roark. “He didn’t want any part of coming out of that game after four. He felt great. If I’d have run him out there for the sixth, he’d have been all for it. He was throwing to corners still. Every pitch mattered to him.”

Roark threw 95 pitches in four innings, raising the possibility that he might not complete the requisite five innings to qualify for the win. But he breezed through the fifth on 14 pitches. The bullpen took care of the rest. So did Jurickson Profar, whose leadoff homer in the sixth lengthened the A's lead to 3-1. That proved essential when St. Louis' Kolten Wong singled home an eighth-inning run.