It appeared Lannan was going to make up for last year's disappointing Opening Day start against the Marlins. In that game, Lannan lasted three innings and gave up six runs on six hits on the road.
But in the top of fourth Monday, Lannan looked like the pitcher who struggled against Florida in last year's opener. Philadelphia batted around and scored five runs.
It was Philadelphia's lefty hitters who started things off against Lannan. Chase Utley led off with a walk. On the first pitch Ryan Howard saw from Lannan -- a slider -- he hit a two-run homer over the right-field fence.
Lannan faced eight more hitters and allowed three more runs in the inning before he was replaced by left-hander Jesse English, who didn't allow a baserunner in 1 1/3 innings.
"Philly is a tough team to stop once they get the momentum," Lannan said. "The momentum kept on going, and I couldn't stop it. I felt good at first, it's just that the fourth inning got me. I felt good the first three innings.
"I wanted to have a different story for Opening Day. It's the first game of many, and I'm not going to let it tell the story for this whole season."
Catcher Ivan Rodriguez said Lannan fell behind in the count too often and had no choice but to throw the ball down the middle of the plate. The Phils took advantage of Lannan's problems on the mound.
"You have to throw the ball over the plate. That's what happens when you are behind the count," said Rodriguez who went 3-for-4 in his debut with the Nationals.
Right-hander Roy Halladay, making his National League debut, pitched like he did with the Blue Jays. He was outstanding. Halladay pitched seven solid innings, giving up one run on six hits and driving in a run with an infield single.
After the first, in which he gave up the RBI double to Zimmerman, Halladay allowed a runner in scoring position just twice the rest of the way.
"He threw a lot of pitches for strikes. He didn't miss too much," Zimmerman said about Halladay. "He was able to get the ground ball when he needed to. I'm sure we will see him plenty more times."
After the game, it was obvious that Halladay enjoyed his first game as a member of the Phillies.
"It was a lot different, I think," he said. "It's been fun for me. Again, nothing against Toronto, but it kind of gives you a renewed energy coming over here. The guys have been great. The team obviously is a team that wants to win and can win. It's fun for me. You feel like you're just out there chipping in, really, the way these guys go about their business. You're just trying to just fill in a role."
Meanwhile, the Nationals' relief corps continued to have problems. Right-hander Miguel Batista allowed five runs and walked four in 1 2/3 innings, and right-hander Jason Bergmann gave up a seventh-inning grand slam to Placido Polanco. Three of those runs were charged to Batista.
"I think the walks would be the negative," manager Jim Riggleman said. "When you are walking people, not much good is going to happen. It speaks for itself."