OAKLAND, Calif. — Brandon Hyde wondered when the big hit would arrive. He sweated out a series-opening win Friday, endured a heavy defeat Saturday and then, with two outs in the first inning Sunday, the Orioles manager watched as the big hit arrived.

It came courtesy of Heston Kjerstad, the rookie outfielder who has done nothing but produce since returning to the major leagues. Kjerstad saw a cutter over the middle of the plate and throttled it 406 feet at 107.4 mph for a three-run homer, and finally, at the end of a weekend at the Coliseum, the breakthrough had arrived.

Baltimore needed that long ball from Kjerstad, because the offense largely dried up as the game progressed. And, for how dominant right-hander Grayson Rodriguez was through five innings, the Athletics chipped away in the sixth and seventh.

But the three-run homer from Kjerstad still proved the difference in the Orioles’ 6-3 victory, which ended their West Coast road trip with four wins in six games. And, with that swing, Kjerstad continued a torrent pace in 10 games since arriving from Triple-A Norfolk.

“Heston can swing the bat, and I think he’s really starting to show people that he can,” Rodriguez said. “I think the league’s about to get a wake-up call about him. Because the way he handles the bat is impressive. He’s got some juice. You see it during BP, and it’s starting to show during the games.”

Kjerstad is 11-for-30 (.367) with 12 RBIs in these 10 games. He’s playing more regularly this go-around, and he’s making the most of these opportunities. Kjerstad has recorded a hit in six of his last seven games.

With the more regular playing time, Kjerstad said he’s feeling in a better rhythm.

“The more at-bats you can get, the more consecutive games you can play, it kind of helps you get into a rhythm or stay in a rhythm,” Kjerstad said. “But, also, it’s the game of baseball. Whenever your name’s called on, whether you’ve gotten to play every day or you haven’t played in a couple days, you’ve got to show up and do your job and help the team win.”

Sunday also marked the final time the Orioles will play a game at the Oakland Coliseum, leaving their regular-season record against the Athletics at 146-147. There have been highs, such as the American League Championship Series sweep in 1971 that concluded here with Jim Palmer’s complete game.

In more recent times, Gunnar Henderson blew past a cycle by stretching a single into a double last year. He didn’t produce that sort of magic in the finale, but Henderson drove in an insurance run in the ninth inning.

Before Henderson’s late RBI single, nearly all of the Orioles’ offense came from four plate appearances in the first inning against Athletics rookie Mitch Spence. Anthony Santander homered to begin the stretch, Ryan O’Hearn and Jordan Westburg singled, and then Kjerstad blasted off to left-center field.

“He’s got that power potential, and he’s taking good at-bats,” Hyde said. “He’s popping one every once in a while and getting some big hits for us.”

That four-spot held until Oakland’s third error brought home another run in the third inning. And, with a three-run lead by the ninth, right-hander Craig Kimbrel’s save opportunity was routine.

After the game, Hyde told the Orioles they played “championship baseball” while on the West Coast.

“If we’re able to go 4-2 like that, that’s big,” Rodriguez said. “That’s going to carry us deep into October.”

Rodriguez extended his scoreless innings streak to 13 1/3 frames through five innings Sunday. After allowing seven runs against the Houston Astros on June 21, the Orioles right-hander has compiled three straight quality starts. He hit a bump in the sixth inning, though, when Tyler Soderstrom drove an RBI double and Shea Langeliers added a sacrifice fly.

Hyde kept him in for the beginning of the seventh, but two singles to begin the frame spelled the end of Rodriguez’s outing. The win gave him 11 this season, which Hyde said is “unbelievable right before the break” for a pitcher in his first full season.

Right-hander Jacob Webb, who entered out of the bullpen, allowed an inherited runner to score — although if Henderson’s throw from shortstop had been on point it might’ve been an inning-ending double play instead. Still, Rodriguez put together a strong showing that included 17 whiffs, with seven of them coming on nine swings against his changeup.

“I feel like throwing the changeup better has allowed me to pitch deeper in the ballgame,” Rodriguez said. “Obviously, the defense has been spectacular. So any time you’ve got guys making plays behind you, it’s really easy to pitch deep into the game.”

It’s even easier, Rodriguez said, when the offense immediately produces run support. After a road trip that lacked a timely knock most nights, Kjerstad delivered one straight away.