SAN FRANCISCO -- Jake Irvin had five days to let the newness sink in. Since his Major League debut last Wednesday at Nationals Park, he traveled with the team to Phoenix and then on to San Francisco, where he took the mound on Monday for his second big league start.

Irvin pitched like someone who had been there before, en route to his first big league win.

“Same 60 feet, 6 inches,” Irvin, 26, said. “But definitely a different atmosphere -- you don’t have the crowd behind you. But that’s kind of what the Minor Leagues is for, I think. You kind of feel that on the way up and you learn a lot about that. So same thing: Just keep making pitches.”

The right-hander hurled a career-high 6 1/3 innings -- the most he had thrown on any level -- in the Nationals’ 5-1 victory over the Giants on Monday at Oracle Park. He was in command with four hits, no runs, three walks and five strikeouts across 92 pitches (54 strikes).

“I think the biggest thing is he used his fastball well,” said manager Dave Martinez. “He threw a few more changeups -- the changeup was really, really effective today. [He was] landing his curveball for a strike, which he’s worked on and he did it well today.”

Irvin is only the second Nationals pitcher to reach the seventh-inning mark this season, joining veteran southpaw Patrick Corbin (seven frames on May 4 vs. the Cubs). Ranked as the Nats’ No. 20 prospect by MLB Pipeline, he also is the fourth rookie in the Majors to throw at least 6 1/3 innings without giving up a run this year.

“He’s got a lot of poise,” said Martinez. “[He] doesn’t let anything rattle him, and he just tries to attack the strike zone.”

Martinez made the call to the bullpen for reliever Carl Edwards Jr. after Irvin allowed a one-out single and a walk. Edwards prevented the runners from scoring, and Irvin’s ERA dropped to 0.84.

“He wasn’t laboring ... mechanics were good,” Martinez said. “I said, ‘He’s got to learn; he’s got to learn how to go deep in games,’ and I thought he did a good job. He got two guys on, and I thought that was perfect.”

Irvin was called up to the Nats from Triple-A last Wednesday after starting right-hander Chad Kuhl was placed on the 10-day injured list because of right foot metatarsalgia on May 1 (retroactive to April 30). Irvin allowed two hits, one run and four walks with three strikeouts over 81 pitches (45 strikes) against the Cubs. Since then, Irvin focused on consistency, getting ahead of batters, winning 1-1 counts and putting opponents away.

“[He was] throwing more strikes than last time,” said catcher Keibert Ruiz. “He was making pitches when we needed to, a couple ground balls for double plays helped us there, so that’s good for him.”

Irvin lauded Ruiz for being a “calming presence” in his debut, and the pair has continued to develop a chemistry in the past week. Together, they achieved the Nationals’ goal of Irvin reaching 90 pitches.

“He calls a fantastic game,” said Irvin. “Having him back there and knowing that he knows exactly what the plan is going into these starts and the way that he prepares himself, it gives me a lot of confidence and makes it a heck of a lot easier for me to make pitches.”

Irvin is realizing the goal that began when the Nationals selected him in the fourth round of the 2018 Draft. He’s showcasing his potential, 3,000 miles away from D.C.

“I absolutely loved watching him pitch, I really did,” said Martinez. “I enjoyed it very much. For a second start, he did really well.”