When Seth Beer got the call to the big leagues, he said the moment felt perfect. The 24-year-old, who was fly fishing at the time, said the moment felt like a dream come true, considering how much he's worked to get to the Majors.

During his first game with the D-backs on Friday night, Beer had a dream start to his MLB career.

Beer, the D-backs' No. 12 prospect per MLB Pipeline, hit a solo home run in his first career at-bat in the D-backs' 5-4 loss to the Mariners at T-Mobile Park. Pinch-hitting for Christian Walker with two outs in the eighth inning, Beer sent a sinker from right-hander Diego Castillo just over the right-field wall.

• Box score

“I kind of went from one dream to another dream,” said Beer, who had his parents, sister, girlfriend and his girlfriend’s family at the ballpark. “Of course every kid when they think about coming up in the big leagues and getting the chance to hit, your first thought is, 'Oh man, I’d love to hit [a homer]. … That's like the best thing you can possibly do.’ So I kind of moved from that dream to the one [now]. I'm just floating on cloud nine right now. It's just so special.”

• Players with home run in first at-bat

Beer was called up ahead of Friday's game after having a strong 2021 season for Triple-A Reno. He slashed .287/.398/.511 in 100 games with the Aces, and he led all Triple-A players with 73 runs scored and was tied for the lead with 49 extra-base hits at the time of his promotion. Across three years in the Minors -- which also included time in the Astros' system -- Beer hit .292 with a .901 OPS.

Beer said he felt nervous when he was told he would be pinch-hitting for Walker. He said he looked at the bullpen camera, saw Castillo warming up and realized he could be facing the right-hander who Beer said was someone he had watched on TV “so many times.”

“When I was walking up to the plate, I just tried my best to just clear my head and not think about anything but just the pitch at hand,” Beer said. “Throughout the at-bat, I really was just trying to go up there and honestly just hit the ball and just try to do something for some damage and just barrel it up. I wasn't afraid to fail. I felt like, in that situation, I was just up there and just competing to the best of my ability.”

Beer became the fourth player in D-backs history to homer in his first MLB at-bat, joining John Hester (Aug. 28, 2009), Gerardo Parra (May 13, 2009) and Alex Cabrera (June 26, 2000).

However, Beer wasn't the only Arizona rookie to go deep for the first time on Friday night. In the second inning, Henry Ramos, a 29-year-old outfielder, launched his first career homer in his fourth MLB game after a long-awaited callup.

Ramos, who spent 11 years in the Minors before getting called up on Sept. 5, belted a two-run homer to left field off Mariners left-hander Marco Gonzales.

D-backs manager Torey Lovullo said the loss was frustrating, but both rookies should cherish the milestones.

“I'm never in a good mood no matter what the circumstances are when we lose a baseball game,” Lovullo said. “I don't think anybody should be. I'm going to stop and congratulate them here in the next couple of minutes. I had that opportunity, too, a couple of times inside of the dugout. I'll make sure that we do enjoy it and know that it's a very special moment for both those guys.”