Left fielder Jonny Gomes makes a running catch off the bat of Joey Votto for the final out of the fifth inning. Gomes also drove in two of the Nationals’ three runs Thursday. (Rob Carr/Getty Images)

On May 8, 2009, Jesus Flores reached the high point of a career rocketing upward. He crushed a home run in Arizona, which had become stunningly routine for the 24-year-old catcher. That night, he owned a .314 batting average and a .923 on-base-plus-slugging percentage. He might have been the best thing the Washington Nationals had going for them. There were so many more home runs to come.

Flores has learned how much can happen in 832 days, the time between that blast in Arizona and Thursday night, when his next home run came in the Nationals’ 3-1 victory over the visiting Cincinnati Reds. Flores belted a fastball over the left-center field fence in the fifth inning, his first major league home run since he missed almost two seasons with a torn labrum, since he worried he might not play again.

“It was a good feeling, running around the bases,” Flores said. “It’s exciting and emotional inside. You hit a home run back in the big leagues. I hit a couple in Triple A, but up here is different.”

As Flores walked back to the dugout, he strode past Jordan Zimmermann, the on-deck hitter. Zimmermann and Flores spent most of last year in Viera, Fla., forging a friendship as Flores healed his battered shoulder and Zimmermann recovered from elbow reconstruction surgery. Zimmermann offered his fist, smiled and told Flores, “It’s about time.”

On Thursday night, both back healthy and both still dealing with the aftermath of their injuries, they led the Nationals to a series win over the Reds. Zimmermann pitched 52 / 3 scoreless innings, lowering his ERA to 3.11 and shooting his total innings this season to 1502 / 3. The Nationals will let him make two more starts, after which point he will have slightly surpassed his 160-inning limit, and they will shut him down for the season.

“I’m just going to keep pitching until they tell me to stop,” Zimmermann said. “I watched for a whole year, so I think I can handle a month.”

Flores understands that as well as anyone. The last time he hit a home run, he was becoming one of the Nationals’ most valuable players, a young catcher who could hit for average and power. The next night, a foul tip struck Flores, breaking his right shoulder. Complications led to a labrum tear and major surgery. Within a year, Flores wondered if he would ever play baseball again.

“Some people had their doubts if he’d ever make it back up here,” Zimmermann said.

Flores returned this season, diminished by injury and rust. He plays in the majors now only because Ivan Rodriguez strained his right oblique muscle, and the Nationals need someone to spell Wilson Ramos, their new catcher of the future, every third day or so. Flores remains certain he can still be the player who drilled a home run that night in Arizona.

“Sure, yeah,” Flores said. “I feel healthy. That’s enough for me to be an even better guy than I was before. This year has been more my comeback year, getting used to everything again. There’s nothing I don’t know what to do. Just get used to it, be ready next year.”

Flores walked to the plate in the fifth inning, the game still scoreless. He worked the count to 1-2 against Reds starter Bronson Arroyo, a tall right-hander. Arroyo threw an 87-mph fastball, chest-high and down the middle. Flores took a fierce swing, the bat circling his head with a follow-through flourish, and sprinted for first base.

Flores watched the ball as left fielder Dave Sappelt drifted back, to the warning track, to the fence, until he ran out of room. He leaped at the wall and the ball landed in the visitor’s bullpen.

“I’m just more confident now,” Flores said. “I’m feeling great.”

The home run gave the Nationals a 1-0 lead, enough for Zimmermann. He received two assists from Jonny Gomes — one on his bases-loaded, two-run single in the sixth, one in the field in the fifth.

Joey Votto came to the plate with Brandon Phillips on first base and laced a line drive into the left-field corner. Gomes bolted toward the fence and, even when he reached the warning track, did not slow. He snared the ball just before crashing into the wall at full speed, somehow managing to hold on to the ball as he shook cobwebs out of his head.

“I was worried he might have hurt the wall,” Manager Davey Johnson said.

With his 102nd pitch, Zimmermann put runners on first and third, and Johnson decided he could go no further. Ryan Mattheus came on and struck out Paul Janish. After the game, Johnson found Zimmermann and told him: “Don’t make me have to come out there when you’ve got unfinished business. You’re too good a pitcher.”

“I want to stay out there 120 pitches if I can,” Zimmermann said. “I know it’s still early in the Tommy John process, and I got to keep the pitches down.”

Between innings, Jayson Werth spotted Mattheus stretching in the dugout and asked why. When Mattheus told him he felt a little tightness, Werth alerted Johnson. Mattheus threw three warmup pitches for the seventh and said he felt fine. But head athletic trainer Lee Kuntz came to the mound, followed by Johnson and pitching coach Steve McCatty, and Johnson opted to make a pitching change. Mattheus called the tightness “a non-issue,” but he understood the Nationals’ caution.

When the game ended, Flores walked toward the mound and high-fived closer Drew Storen. He may not be the same player he once was, the promise and possibility having dimmed. But for one night, with one swing, Flores showed at least a flicker of his old self.