ST. LOUIS - The noise inside the Edward Jones Dome on Sunday hurt the Philadelphia Eagles' offensive line more than the St. Louis Rams' defense.

An announced crowd of 56,722 made life difficult for the Eagles at the outset, resulting in a couple of penalties and missed assignments in the first half of the Eagles' 31-13 victory.

"I kind of expected it to be loud," rookie center Jason Kelce said. "But it was really loud. Most of the mistakes we made were because some of the guys couldn't hear the protection calls."

Once the Eagles took control of the game, however, it was less of a problem.

When the Eagles increased their lead to 24-10 in the third quarter on quarterback Michael Vick's 6-yard touchdown pass to wide receiver DeSean Jackson, most of the fans headed to the exits, probably hoping to catch a few innings of the St. Louis Cardinals' game against Atlanta at Busch Stadium.

They were plenty loud at the outset, buoyed by a touching pregame ceremony that honored the memories of the victims of the Sept. 11, 2001 terrorist attacks.

The Eagles were penalized for a delay of game on their first series. Left tackle Jason Peters was called for holding, and Vick was sacked by defensive end Chris Long.

"You have to work through some things in the first game and the first part of the season," Eagles coach Andy Reid said. "That's what we were doing today."

The Eagles' offensive line has undergone drastic changes since training camp opened in late July.

Kelce was flanked by guards Evan Mathis and Kyle DeVan. None of the three were with the Eagles last season. DeVan just joined the team a week ago. In addition, Todd Herremans was moved to right tackle after spending the the majority of the past six seasons at left guard.

But they eventually got into a rhythm and wound up doing a decent job of protecting Vick and opening holes for running back LeSean McCoy. McCoy rushed for 122 yards on 15 carries, including a 49-yard touchdown run in the fourth quarter.

"It felt good to see us run the ball so well late in the game," Kelce said. "As an offensive lineman, you take pride in being able to pound the ball late. When the defense knows it's coming and they still can't stop it, that's a great feeling."

From starter to spectator

Eagles first-round draft pick Danny Watkins went from starter to substitute in the span of a week.

Up until last Sunday, Watkins was scheduled to be the starting right guard against the Rams. Not only was he demoted to second string behind DeVan, he was deactivated for the game.

The Eagles actually deactivated their first three draft picks. Watkins was joined on the inactive list by safety Jaiquawn Jarrett (second round) and cornerback Curtis Marsh (third round).

DeVan, who was claimed off waivers from Indianapolis last Sunday, was called for two penalties - a false start and holding - against the Rams.

Maclin's homecoming

Wide receiver Jeremy Maclin was the only Eagles' player to get cheered by Rams fans during the game.

Maclin, a native of St. Louis, bought tickets for about 20 family members and close friends. But the school district Maclin attended, Kirkwood, also purchased about 1,000 tickets.

Maclin, who missed the entire preseason with an illness, was not much of a factor in the game, catching one pass for 20 yards, but he still had a smile on his face after the game.

"It was a great opportunity for my friends and family to see me play," Maclin said. "Most importantly, I'm happy that we came out with a win."

Inside the numbers

Defensive end Juqua Parker's 56-yard fumble return was his second career touchdown. He had a 55-yard interception return at San Francisco in 2008. ... The Eagles are 6-7 in season openers under Reid and 3-1 since 2008. ... The Eagles improved to 14-5 against NFC West teams since 2002. ... The Eagles have outscored the Rams 69-16 in their last two meetings. ... Alex Henery kicked a 34-yard field goal to become the first Eagles rookie to make a field goal since Paul McFad-den in 1984.

Out of action

In addition to Watkins, Jarrett and Marsh, backup quarterback Vince Young (strained hamstring) was also inactive, leaving Mike Kafka as Vick's only backup. Had both Vick and Kafka gotten hurt, the Eagles would have been forced to use wide receiver Jason Avant at quarterback.

Other inactives: defensive end Phillip Hunt, tackle Winston Justice and guard Julian Vandervelde.

Bumps and bruises

Eagles backup linebacker Akeem Jordan left the game in the first half with a sprained shoulder and did not return. Defensive end Darryl Tapp suffered a strained pectoral muscle while recording a sack in the third quarter and did not return.

Up ahead

Vick will make his first start against his old team when the Eagles take on Atlanta next Sunday at the Georgia Dome. He played a reserve role in the Eagles' 34-7 win at Atlanta two years ago but ran for one touchdown and threw for another. Philadelphia native and Wildwood summer resident Matt Ryan is the Falcons' quarterback.

Atlanta opened with a 30-12 loss at Chicago on Sunday.

Contact David Weinberg:

609-272-7186