WASHINGTON -- On a team that won't quit, there is a 32-year-old rookie who hasn't quit either.

Yadiel Hernandez hit the game-winning home run -- the first homer of his Major League career -- off Brandon Workman in the eighth inning of Game 2 of Tuesday's seven-inning doubleheader against the Phillies at Nationals Park. The Nats exited the field with an 8-7 win, a sweep of the twin bill and their fourth straight victory. They won Game 1, 5-1.

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“I was extremely happy,’" said Hernandez, who also hit an RBI double in a two-run fourth inning for his first Major League RBI. “In reality, it never crossed my mind that I was going to end the game that way. I obviously thought I was going to hit a home run at some point, because that’s part of my game. ... I just didn’t foresee it happening in that moment, where it ended the game on a walk-off home run like that.”

Hernandez became the oldest player in Major League history to belt a walk-off homer as his first career long ball. He’s been making up for lost time this month after chasing his big league dream since 2009, when he began playing pro ball in Cuba.

Hernandez spent the majority of this season at the alternate training site in Fredericksburg, Va., before the Nats selected his contract on Sept. 10. But after going 0-for-7 in his first three games, he was optioned Friday. Unsure if he would get another chance this season, Hernandez -- who was named Washington’s Minor League Player of the Year in 2019 -- was disappointed in his lack of initial success at the plate in the Majors.

“A lot of bad things ran through my head at that moment,” he said. “It was one of the things I kept thinking about -- the fact that the season’s about to end, so there’s a possibility I don’t get another opportunity and I don’t even have a base hit to show for it. It was very frustrating.”

Hernandez didn't have to wait long for another chance. He was with the team for its weekend series in Miami, then he was in the starting lineup as the designated hitter in Game 2 on Tuesday.

The Nationals were trailing, 7-6, when Hernandez stepped to the plate to face Workman, with automatic runner Luis García on second. They had taken an early lead after Juan Soto belted a three-run homer in the third, and they were up, 6-5, through five before the Philies tied it in the sixth and pulled ahead on an error in the eighth.

Hernandez, described by manager Dave Martinez as a student of the game, had watched Workman throw cutters to Eric Thames in the previous at-bat. He expected the pitch, waited out two fastballs and fouled another off before sending a 90 mph cutter a projected 382 feet over the right-field wall to win the game.

“[I was] excited for him,” Martinez said. “You watch him running around the bases -- he was happy as can be. The celebration wasn’t what it typically is, but the boys were jacked up. Good for him.”

Game 2 was appropriately started by a committed pitcher who had also patiently waited for his moment in Fredericksburg. The day after the Nationals called up right-hander Paolo Espino from the alternate training site, the 33-year-old made his first Major League appearance since 2017. He threw four innings, allowing three runs on seven hits, with four strikeouts and no walks over 66 pitches (41 strikes).

“I was so happy to be back,” Espino said. “I’ve been working hard for the past few years. While I was in Fredericksburg, I was doing everything I could to try to earn a spot to be back up here again.”

From beginning to end, the Nationals’ win was anchored by determination from their players -- and those who were appreciative of the moment. After the postgame celebrations ended, Hernandez walked into Martinez’s office. He wanted to thank his manager for giving him another opportunity on this level.

As the Nats added another "W" to their record and continued their pursuit of a final-week playoff push, it was Hernandez who received the thanks from the team.