SAN DIEGO — There was a time, just over a month ago, when the events that transpired on the field at Petco Park on Monday would not have been possible.

Jeremiah Jackson, Samuel Basallo and Dylan Beavers were still in Triple-A, Ramón Laureano and Ryan O’Hearn were still on the Orioles, and Kyle Bradish was just beginning his rehab progression.

But time moves quickly in this league, and those days are long gone for the Orioles. Now, Jackson, Basallo and Beavers are rookies who were responsible all four of the Orioles’ runs. O’Hearn and Laureano are on the Padres, combining for two hits as they faced their former team for the first time since the trade deadline. And Bradish is back on a major league mound, making his second start since returning from Tommy John elbow reconstruction surgery.

It was the new-look Orioles who took Game 1 of the three-game series, beating the Padres 4-3.

Bradish pitched four innings, allowing two runs on four hits while striking out five on 84 pitches. A taxing second inning ended up being his downfall, as he needed 32 pitches to get out of the frame. The Padres scored both their runs off Bradish in that inning, with Bryce Johnson and Luis Arráez each hitting RBI singles.

“Obviously that first start was a lot better,” Bradish said. “I felt like I was just battling command. I was getting ahead in counts and letting them back in or I was pitching behind in counts and letting them foul off a lot of balls. It’s a good hitting team. Obviously, I didn’t have my A-stuff today, but I was able to battle through four, gave up two runs.”

His velocity topped out at 97.8 mph, like it did in his first start, and his fastball averaged 95 mph.

“I’m happy where it’s at,” he said. “I think as the rest of the year goes on, I’ll be able to carry the velo throughout the outing, but it’s just a testament to the hard work I put in over the last 14 months with our training staff and strength coaches.”

A questionable strike zone impacted his outing, as it did for Padres starter Dylan Cease. Basallo was able to hit a two-run double off Cease in the second to give the Orioles an early 2-0 lead. Cease, like Bradish, made it only four innings, bringing on a battle of the bullpens with the score tied 2-2.

In the fifth, Jackson gave the advantage back to the Orioles, hitting his third home run and second of the road trip. Jackson said this is the best he’s felt at the plate, and he’s comfortable at the big league level, despite Tuesday being only his 27th game.

“Just had a plan, trying to see something in the heart of the zone, just tried to be aggressive early, and if he made a mistake, just try to hit that pitch,” he said. “And that’s kind of what happened and I was able to get a good swing off.”

But Laureano, like he did with Baltimore in the first half of the season, came up in a big spot and provided the hit his team needed. He hit an RBI single to tie the game again in the bottom of the fifth.

Leave it to the rookies, who have brought some life back to the lineup, to pull through. In the seventh, Jackson hit a single, his third hit of the day. He advanced to second after a base hit from Gunnar Henderson, and, after a quad injury forced Padres reliever Jason Adam to leave the game and be replaced by Robert Suárez, scored on an RBI single from Beavers.

“One of the great relievers in the game, Suárez, goes up there, think it was two strikes and think it was maybe a changeup and hits the game-winning hit right there, which is pretty awesome to see,” interim manager Tony Mansolino said.

The Orioles held on to the 4-3 lead, with Dietrich Enns, Rico García and Keegan Akin pitching scoreless relief appearances.

With Tyler Wells set to make his first start in 14 months after elbow surgery, the Orioles needed to ensure they didn’t blow through their bullpen in case Wells has a short start Tuesday.

“We hung in there,” Mansolino said. “Listen, we’re just trying to piece this together. I’ve told you guys there’s gonna be days where it works and there’s gonna be days where it doesn’t. We’ve got guys kind of pitching up in terms of like roles they’re throwing, and today it worked out. I’m proud of the guys. They did awesome, and we were kind of due for a good one, so happy for that.”