After President Barack Obama's first pitch at Nats Park went high and wide, the Nats quickly went south, losing 11-1.
Also a familiar sight when the Phillies come to town -- there seemed to be as many Phillies fans as Nats fans in the stands.
"I think it's great for the sport, I really do," said Commissioner Bud Selig, putting a positive spin on the Phillies' road support. "There's enormous interest, obviously, in Philadelphia and the fact that people travel as much as they do now. ... It's only a testament to this game's popularity."
In his first Opening Day as the starting shortstop -- a job he wrested from Cristian Guzman in spring training -- rookie Ian Desmond booted a grounder up the middle. Desmond was shifted to the first base side of second base as lefty slugger Ryan Howard stepped up to the plate. Fortunately, Phillies shortstop Jimmy Rollins, who stole second with two outs, tried to score from second but was thrown out by first baseman Adam Dunn.
The Nats scored first in the bottom half of the inning when centerfielder led off with a single and third baseman Ryan Zimmerman drove him home. That run broke Phillies pitcher Roy Halladay's 24-inning scoreless streak dating back to his last three games with the Toronto Blue Jays last season, but that was the last run the Nats would push across.
The centerpiece of the Phillies' drive for a third straight World Series appearance, Halladay struck out nine over seven innings and allowed six hits in his debut for the Phillies. He even helped himself at the plate with his second career RBI, albeit on a dribbler that traveled all of about 30 feet in Philadelphia's five-run fourth inning.
New Nats catcher Ivan Rodriguez, in his 19th consecutive opening day start, doubled to lead off the second, but Halladay then faced the minimum number of batters -- with help from a pair of double plays -- until the seventh, when he worked out of a two-on, one-out jam.
The Phillies' scoring began in the fourth inning with a two-run home run from Howard to seize a 2-1 lead. It ended with a grand slam from third baseman Placido Polanco in the seventh inning. Polanco went 3 for 5 and had a career-high six RBIs.
John Lannan (0-1), the Nationals' opening day starter for the second year in a row, lasted only 3 2/3 innings, allowing five runs and seven hits with three walks and no strikeouts. Eight of the 10 batters he faced in the fourth reached base.
The Phillies' win broke a streak of four consecutive opening day losses. It ended the Nationals' seven-game winning streak dating to the end of the 2009 season.
Zimmerman, Dunn and Lannan were the only three Nationals starters from the Nats 2009 opening day lineup. Prior to the game, Zimmerman was awarded his Gold Glove and Silver Slugger awards before the game.
Rodriguez had three hits, including a pair of doubles.