SEATTLE — For the better part of the first quarter of Sunday's game against the Philadelphia Eagles, the Seahawks were that team again.

The one that in years past cranked it up a notch and sent the home crowd into a frenzy with ferocious defense and offensive execution. The Seahawks pressured Eagles quarterback Donovan McNabb and forced him to make bad throws from the get-go, then hit the jackpot on their first offensive play of the game with a long touchdown pass.

Then, in an instant, the early momentum was gone. The undermanned Seahawks couldn't maintain the intensity with which they started, couldn't get key stops on defense, made several errors on offense and fell to the Eagles 26-7.

Philadelphia (5-3) scored 26 unanswered points and shut down the Seahawks' offense, sucking the life out of Qwest Field as the home team slogged through another mystifying performance.

"There were a couple of instances where it looked like, heck, if I was sitting in the stands I would ask, 'What the heck are 1/8the Seahawks3/8 doing?' " coach Mike Holmgren said. "That leaves a bad taste in my mouth."

Winning was a challenge even before the game started. The Seahawks were without Pro Bowl defensive starters Lofa Tatupu and Patrick Kerney, both out with injuries. Fullback Leonard Weaver, the star of last Sunday's win at San Francisco, was active but didn't play.

But the Seahawks showed plenty of life early. On their first snap on offense, quarterback Seneca Wallace found wide receiver Koren Robinson with a long pass, and Robinson took off.

He avoided one tackle, got a block from teammate Bobby Engram and outran a second tackler on his way to a 90-yard touchdown to give the Seahawks the early lead. The stadium was rocking, having witnessed the longest play from scrimmage in franchise history, and the defense fed off it.

Defensive tackle Brandon Mebane and linebacker Julian Peterson forced McNabb to hurry two passes. Cornerback Marcus Trufant broke up a third-down pass and then, uncharacteristic of his calm demeanor, let out a scream.

When the Eagles did get their first long drive of the game, Seahawks safety Deon Grant ended it with an interception in the end zone.

"We really felt like we were on our game early," safety Brian Russell said. "The rush was getting home, driving them nuts. We were breaking up a lot of balls, and then the momentum turned when we stopped making those plays."

The good vibes and momentum fizzled fast, and the Seahawks went back to resembling the 2-6 team that they are. The downturn began when tight end John Carlson dropped a sure first-down catch on third-and-eight from the 50 with 11 minutes left in the second quarter, forcing the Seahawks to punt.

Philadelphia's offensive line settled down, made adjustments and gave McNabb time to throw. The veteran quarterback picked apart the Seahawks' one-on-one coverage with relative ease, going from 3 for 13 in the first quarter to completing all 11 of his second-quarter passes and continuing his stellar play in the second half.

McNabb engineered a six-play drive on Philadelphia's first possession of the second quarter, finishing it off with a 22-yard touchdown pass to Reggie Brown on which Brown shook Trufant's tackle. The next time the Eagles got the ball, they ran 11 plays, the biggest a 26-yard hookup with Kevin Curtis to the 1-yard line that set up another touchdown.

It was 14-7 Eagles at halftime, and Philadelphia was in control.

On defense, the Eagles overcame the shock of the Seahawks' first play and dominated for much of the game. The Seahawks failed to get a good running game going for the second straight week, and Wallace was often on the run from the Philadelphia pass rush, which sacked him four times.

"They are trying hard. It breaks my heart," Holmgren said of his players. "It breaks my heart, but we're not getting enough to show for it."

By the start of the fourth quarter, fans had begun streaming out of the stadium. The Seahawks punted 11 times, unable to move the ball. And though the defense gave up just four field goals in the second half and did well against the run, it didn't have an answer for McNabb or his favorite target of the day, second-year tight end Brent Celek. He caught six passes for 131 yards, an Eagles record for receiving yards in a game by a tight end.

Seattle fell three games out of the lead in the NFC West.

"The only thing we can do is keep trying to play and try to dig ourselves out of this hole," Wallace said.