MIAMI - At about 4:05 p.m. ET on Tuesday, Collin Balester walked into the Nationals' clubhouse at Dolphin Stadium, unloaded his big, dark-blue duffle bag on the floor and exhaled while surrounded by the lockers of all of his new Nationals teammates.

"It's good to be here," he said.

Balester was called up from Triple-A Columbus after the Nationals' extra-inning loss on Monday. And in a few hours, he would be making his Major League debut against a team that was 9-1 against Washington this season and leads all of baseball in home runs.

It seems like the 22-year-old was up for the challenge.

Balester pitched five innings of one-run ball and notched his first big league win when the Nationals took care of the Marlins, 9-6.

"Once I got up there to warm up, I was a little nervous, and I was just sitting out there looking at everything. It was amazing, the fact that I finally made it to the big leagues," said Balester, who had his parents, sister, girlfriend and high school baseball coach from California at Dolphin Stadium on Tuesday. "I got into a little trouble in the fifth but, for the most part, I couldn't have scripted [my first start] any better."

Balester gave up only one hit while walking three and striking out three before exiting the game with the lead. He threw 95 pitches -- 54 for strikes. The 6-foot-5 righty did not allow a hit through the first four innings while tossing just 64 pitches through those frames. Balester finally ran into a little trouble in the fifth.

That inning saw him walk opposing pitcher Mark Hendrickson on four straight pitches, face seven hitters and give the Marlins their first run. But Balester was able to work out of a bases-loaded, one-out situation with only one run across and, at that point, a 2-1 lead intact.

After the game, Nationals manager Manny Acta said the organization hasn't had an arm come through its farm system like Balester since Javier Vazquez.

"He was very impressive," Acta said. "The fact that he kept battling, and he kept pumping strikes to the good hitters of the lineup in [the fifth] inning, it says a lot.

"He's not afraid. He just needs to slow the game down a little bit."

Balester sports a low- to mid-90s fastball, an above-average curveball and a changeup he's been using a lot more frequently. To help him out with his nerves, the Nationals gave veteran catcher Paul Lo Duca the start behind the plate. Since returning from the disabled list on June 17, Lo Duca has started seven games, but only one -- June 21 against the Rangers -- had been at catcher.

But Acta went with Lo Duca --- who went 2-for-4 with two runs scored on Tuesday -- mainly because of the 36-year-old's experience handling young pitchers.

"I tried to go out there like 10 times to just try to calm him down. He was so amped," Lo Duca said. "It's just a matter of him harnessing it a little bit. He's got an electric fastball, an electric curveball, and he's going to be good for a very long time.

"I told him before the game, 'This is your game. You belong here.' And that's the way you have to look at it."