It’s all high-fives and fist bumps for Nationals starter Brad Peacock, who is greeted in the dugout after delivering 5 2/3 scoreless innings on 69 pitches as Washington rolls to a sweep. (Matt Slocum/Associated Press)

Ignore, for a moment, their irrelevance in the standings, and the past three days here have unfolded like some kind of fantasy for the Washington Nationals. The finally stood up to the bullying Philadelphia Phillies, sweeping them for the first time since baseball returned to Washington – over four games on the road, no less. Three promise-packed starting pitchers – not even the ones named Strasburg and Zimmermann – allowed no runs in their respective starts. Each game seemed like it could not get better, and then it did.

The culmination came Thursday night in the Nationals’ 6-1 victory at Citizens Bank Park, when Brad Peacock pitched 5 2/3 scoreless innings in his second career start. Peacock, a 23-year-old right-hander, retired 17 of the 20 batters he faced, and the lone hit he allowed did not leave the infield. As a starter, Peacock has begun his career with 10 2/3 scoreless innings on three hits and five walks.

Peacock has validated the widely held belief he ranks among the best 50 prospects in baseball. He has also made an impression. When it comes time to choose the Nationals’ roster next spring, Manager Davey Johnson said he will remember Peacock’s performance.

“That’s what I wanted to do, just open some eyes up,” Peacock said. “I think that’s what I’m doing.”

The Nationals, really, could not have asked for more out of the final portion of their schedule. They have received standout performances from youthful starters, which seems like their most plentiful and valuable commodity. Tom Milone, Ross Detwiler and Peacock combined to throw 19 scoreless innings over the past three days.

“These guys have done a great job breaking into the big leagues,” Johnson said. “They’re trying to make the case that they want to stay here. Intra-team competition is the best thing is the world you can have to make your ballclub better. They certainly have put notice to some other guys around here that ‘We want your job.’ And that’s a good sign.”

Stephen Strasburg, who will start Friday night, has pitched well and, more important, looked healthy. And the Nationals have won eight straight on the road, 10 of 12 overall, to push their record to 76-79. If they finish 5-1 or better, they will have their best record since relocating.

As a bonus, they thrashed their nemesis. The Phillies have already clinched the best record in the National League and they rested plenty of starters. But surely they did not want, or anticipate, the smackdown delivered by the Nationals, who outscored them 20-9 in the four-game series. The Nationals won nine of their final 11 games against the Phillies and took the season series, 10-8. The Phillies beat them 51 times in 72 games the previous four years.

“For us, there’s certainly significance,” General Manager Mike Rizzo said. “That’s probably the best team in the National League. We’re showing them that we belong with them and we’re going to be a team to be reckoned with in the future.”

Not everyone could ignore the Nationals’ spot in the standings and the status of the two teams. In another corner of the Nationals’ clubhouse, shortstop Ian Desmond splashed cold, reality-spiked water on the sweep.

“We’ve got six games left and we’re going home,” Desmond said. “They’re going to the playoffs. So it’s not that important. They didn’t have their full lineup out there one game we played against them. Obviously, it’s nice to beat Philly. I don’t want to be disrespectful of the guys they had in there. That’s not what I’m trying to do. They’re going to the playoffs. We’re going home. Next year, we’ll see. We beat them next year, then I’ll be happy.”

Thursday, Michael Morse delivered the decisive blow Thursday in the eighth inning with his 28th home run, smashing a three-run blast into the Phillies’ bullpen beyond the center field fence. Roger Bernadina added two RBI.

The unquestioned star, though, was Peacock. He needed only 69 pitches, pummeling the strike zone with his low-90s fastball and change-up. “That’s what was working,” he said. “That’s what I stuck with.” He needed only 10 curveballs and struck out just two, content to let the Phillies hit lazy flies early in the count.

“The way he attacked that lineup, he just went at them,” reliever Ryan Mattheus said. “He wasn’t intimidated a bit.”

Peacock came close to threatening a no-hitter. With two outs in the second, Carlos Ruiz hit a hard grounder down the third base line. Ryan Zimmerman made a diving stop, leaped to his feet and fired across the diamond. An accurate throw likely would have retired Ruiz, but the ball sailed well over first baseman Laynce Nix’s head. The official scorer gave Ruiz a single and Zimmerman for an error for the runner’s advancement to second.

Peacock would not allow another hit. He retired the next 11 batters he faced, at which point, suddenly, came the only blemish of his night. Phillies fans began furiously waving white towels in the stands, and “that got me a little bit. I saw those towels out there, and I got a little nervous,” Peacock said. “I had never experienced anything like that. It kind of got me pumped at the same time.”

He lost feel for his fastball, sailing several over the strike zone as he walked pitcher Roy Oswalt and Jimmy Rollins with one out. He got Shane Victorino to fly out to center, but Johnson called on lefty Tom Gorzelanny. Gorzelanny walked Chase Utley, but preserved Peacock’s sterling final line by inducing a fly out from Raul Ibanez.

The Nationals left Philadelphia for this year still without any hope for the postseason, but perhaps a little more for what lies beyond it. “This,” Morse said, goes straight into next year.”