WASHINGTON - Not until he saw the shoes did reality sink in.

Over the previous 24 hours, Roy Oswalt had blessed a trade from his longtime team, said goodbye to his longtime teammates, and hopped a flight from Houston to the nation's capital to begin the next chapter in his career. But it wasn't until he slipped on his new uniform and looked down at his cleats that he finally took pause.

"The red shoes, actually, were the thing that looked so different," Oswalt said last night after making his Phillies debut in an 8-1 loss to the Nationals. "I'm used to the black shoes."

There are a lot of things that Oswalt is used to that changed when the Phillies acquired him for a three-player package fronted by 27-year-old lefthander J.A. Happ. Even after the Astros defeated the Brewers behind Happ's six scoreless innings and the Phillies fell to the Nationals behind their new starter, Houston still had 13 fewer victories and nonexistent playoff hopes.

Oswalt, who at 32 has a slew of top-5 Cy Young finishes, has gone from playing out the string for a rebuilding team to joining a high-priced rotation that the Phillies hope will help them catch either the Braves in the NL East or the Giants in the wild-card standings.

After last night, they are 3 1/2 games back in the first pursuit, and at least two games back in the second.

The first pitch Oswalt threw in his new uniform ended up streaking through the alley in right-centerfield for a leadoff triple that left Nyjer Morgan standing at third. The Nationals took a 1-0 lead on a groundout by Adam Kennedy, then added two runs in the third and two in the fifth to seize a 5-0 lead.

Oswalt's final line: six innings, seven hits, five runs, four earned runs, two walks, two hit batsmen, and four strikeouts.

"You don't try to think about it, going into a new clubhouse, trying to get to know the guys, and know the personalities," said Oswalt (6-13, 3.53), who joined the Phillies at their team hotel late Thursday night. "But when you get on the field, it's still baseball, and you have to perform at the top of your game. Today, I started out on the wrong foot with the first batter. I think next start I'll be a little bit better tuned, I guess you could say."

The Phillies didn't help their new starter, tallying just six hits and committing a costly error in the third, when third baseman Greg Dobbs took responsibility for a play in which catcher Carlos Ruiz fielded a bunt and instinctively tried for the force out at third, which Dobbs had vacated when charging the play. Ruiz' throw to the vacant base ended up in left field, allowing one run to score and a runner to go from first to third (one of the Nats' two runs was charged to Oswalt, although perfect execution on the play might have resulted in a doubleplay).

Oswalt was plagued by shoddy run support in Houston, where the Astros averaged an NL-low 3.14 runs per 27 outs when he was on the mound. Last night, his new team didn't score its first run until the seventh inning, when Jayson Werth hit his 15th home run to cut the deficit to 5-1. Later in that inning, Oswalt was replaced by pinch-hitter Ben Francisco, who struck out with a runner on second to end the frame.

Top prospect Domonic Brown went 2-for-4 with two strikeouts, and red-hot leftfielder Raul Ibanez had two hits and a walk, but the Phillies fell well short of extending their season-best eight-game winning streak, prompting new questions about their differing performances on the road, where they are 24-30, and at home, where they have won 11 straight and are 32-17.

Road woes are not uncommon in baseball. Four of their five closest competitors in the wild card have similar road records, as do the Braves, who are 25-30 away from Turner Field after last night's win in Cincinnati.

"We've played good on the road the last few years," manager Charlie Manuel said. "We got out of the gate good this year on the road, and then all of the sudden we've struggled. That's kind of the way it goes at times. But we can still play good on the road. If we're going to win, we'll definitely have to play better on the road than we have been."

Everywhere probably feels like the road for Oswalt, who said that various reports that suggested he was hesitant of playing in Philly were completely untrue.

"It's good to get it out of the way," said the Mississippi native, whose next start will likely come in Florida on Thursday. "Everything was kind of going around my start, so get it out of the way and maybe next time will go a little bit better."

For more Phillies coverage and opinion, read David Murphy's blog, High Cheese, at http://go.philly.com/highcheese. Follow him on Twitter at