ST. PETERSBURG, Fla. — It was a low curveball, well below the strike zone from right-hander Phil Maton, but Adley Rutschman’s swing dug out the pitch anyway.

The long blast that followed his golf-like swing left each hose of the homer hydration station occupied, and the grand slam turned what had been a close contest into a blowout in the Orioles’ favor. Rutschman’s career-high six-RBI performance was the catalyst for Baltimore’s 9-2 victory over the Tampa Bay Rays on Sunday in the third game of a four-game series.

Rutschman also drove in runs in the third and seventh innings. With each knock, he elevated his team-leading batting average to .306 with 49 RBIs.

“I think Adley’s one of the first guys you want up in any situation,” manager Brandon Hyde said. “Just the at-bats he takes, he can really hit. You’re always happy when he’s up at the plate.”

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As is often the case with this lineup, Rutschman wasn’t alone. Right-hander Grayson Rodriguez gave a platform for the offensive eruption by pitching five perfect innings before a slight stumble in the sixth inning. Anthony Santander blasted his 14th homer of the year, and three Orioles hit triples, including the much-beleaguered Cedric Mullins.

For three straight days, Hyde kept Mullins in the lineup despite a slump that lowered his average to .170 entering Sunday. He did so, Hyde said, because he figured the best way to inspire confidence within Mullins was to exhibit the confidence the Orioles felt in him.

There will need to be more positive outcomes at the plate over a longer extension of time before Mullins can be considered out of the woods, but with two hits in Baltimore’s win against the Rays, there was at least a sign of life — signs that Mullins could overcome the mire that has thickened around his feet in the batter’s box.

“It’s been tough, but being that it’s a long season, it is a matter of getting your mind right,” Mullins said. “And, once you feel your mechanics are in sync for the most part, it is a matter of getting that mental down and trying not to put too much on yourself.”

Before his two hits, Mullins was locked in an 0-for-25 slide. He hadn’t recorded a hit since May 27, and his last multihit game was May 23. Between May 23 and Sunday, Mullins had notched only one knock.

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And yet Hyde kept playing Mullins, because he believed (or at least hoped) a turnaround was possible.

“You want it to be one day that ignites it, but when you’re going through a tough stretch, there’s no promises of how long or short it’s going to take,” co-hitting coach Ryan Fuller said. “When you go into that cave, when it’s dark, you don’t know how long you’re going to be in there. But it makes you look at things a little bit differently, and if you stay in there long enough, you’re usually going to find that light that comes out the other side.”

Gunnar Henderson of the Orioles scores a third-inning run. (Douglas P. DeFelice/Getty Images)

To extend Fuller’s metaphor, perhaps Mullins is now seeing the light, at least.

Mullins’ triple to begin the seventh came at an opportune time. Rodriguez, who looked untouchable through five, walked one and allowed two singles in the sixth, with the latter single from Brandon Lowe driving in a run. Right-hander Dillon Tate entered and conceded an inherited runner too.

Rodriguez was in “total, complete command for almost six innings,” Hyde said, and the dominance continued what has been a strong stretch for Baltimore’s pitchers. Rodriguez, in his second season as a major leaguer, has reached a new level of start-to-start consistency. He built off strong outings from Kyle Bradish and Cole Irvin in the first two games of the series, too, even if Rodriguez was disappointed by the runs off him in the sixth.

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“Wish I could’ve pitched deeper into that game,” Rodriguez said. “Started off pretty good. Didn’t finish it near how I wanted to. I wanted to keep the bullpen out of it for a little bit longer.”

But to lead off the seventh, in a left-on-left matchup, Mullins helped to push Baltimore’s lead back to a more comfortable distance. Rutschman soon drove Mullins home with one of his three hits.

“Baseball’s a tough game, ’cause it’s just unlucky at times,” Rutschman said of Mullins. “He’s been hitting the ball really hard, at good angles. A lot of lineouts. So I think everyone knows it’s just a matter of time. He looks really good at the plate, so it’s nice to see some of those fall today.”

The loudest knock, however, came in the eighth. With bases loaded, Rutschman battled in an 0-2 count by fouling off two pitches. “Just trying to get some pitch I can do damage on there,” Rutschman said. Then came the low curveball, the golf swing, the grand slam and the hydration station.

For a third straight day, a complete team performance thundered the Orioles past the Rays.