Roy Oswalt took the mound for the Philadelphia Phillies just one day after he was traded to the organization in a four-player deal. Oswalt, who was just 6-12 this year with Houston, did not respond well in his first outing and was roughed up as the Phillies lost to the Washington Nationals 8-1 on Friday night.

“I came out amped up, held the ball a little tight,” said Oswalt, who absorbed his major league-leading 13th defeat. “Didn’t really start feeling better until the last two innings. Didn’t really go my way.”

Oswalt was a former 20-game winner with Houston but has struggled all year. He gave up five runs and seven hits in 6 1/3 innings in the loss. This was an important game for not only Oswalt, but the Phillies also as Philadelphia is chasing the first-place Atlanta Braves in the NL East.

“It’s different for sure,” he said. “This team is good from top to bottom. It’s good to get on a pitching staff with [Roy] Halladay and [Cole] Hamels and the other guys. It’s hard to gain 30 games overnight.”

Possibly starting Oswalt against a different opponent for his debut might have been a better option based on history. In his last start against Washington back on May 31, Oswalt lasted only 2 1/3 innings. He gave up four runs and was ejected for arguing balls and strikes. Washington’s Nyjer Morgan could have not said it any better when asked about the game and Oswalt’s performance.

“Same Oswalt. He’s got electric stuff. We just jumped right on him,” Morgan said.

Despite his performance in his debut, Phillies manager Charlie Manuel knows that good things are going to come from Oswalt.

“His stuff was good. [Oswalt] was having a little trouble with his command. … They kind of ambushed us from the start,” Manuel said. “I like his stuff. He’s going to be fine.”

Adam Kennedy led the Nationals at the plate and had a season-high four hits. Craig Stammen (3-4) got the win for Washington. He carried a shutout into the seventh inning and gave up just one run and five hits while striking out five.

“I just got in a groove and had a pretty good sinker,” Stammen said. “We got a lead so it was pretty much throw that over the plate and see if they could hit it. For the most part, I did all right tonight.”

The loss now puts Philadelphia at 56-47 on the year and puts them 3 1/2 games behind the Braves. The loss also ended their eight-game winning streak. Washington now moves to 45-58 after their win, but still are last in the NL East and trail Atlanta by 14 1/2 games.