SEATTLE -- Quarterback Russell Wilson reminded everyone late Sunday night -- including the Philadelphia Eagles -- that it's not how you start in the NFL, it's how you finish.

"It's December. It's time to play. It's time to be great," said Wilson, helping to explain how his Seahawks put forth their best performance of the season to down the first-place Eagles, 24-10.

"You always want to have this constant progression. You always want to have this growth. It's always great to start out undefeated or something like that but the key is, can we get better?"

That's the fundamental question facing the Eagles as they sort through what happened at CenturyLink Field and set their sights on the final quarter of the regular season, beginning with a monster road game against the Los Angeles Rams on Sunday.

Carson Wentz and the Eagles did not match Seattle's intensity on Sunday. Otto Greule Jr /Getty Images

Certainly, there's no need to panic. They are tied atop the NFC at 10-2 with the Minnesota Vikings and are one win or a Dallas Cowboys loss from claiming the NFC East. They're well-positioned and full of talent. A loss at unfriendly CenturyLink Field to a formidable opponent is nothing to get too worked up about.

It did knock the aura of invincibility off this team, though, while driving home the point that the level of intensity and competition is going to go up as the postseason nears. At least on this night, the Eagles were unable to match it.

"Like I told the team after the game, you can't just show up and expect to win against good football teams," said coach Doug Pederson. "They are really good in the month of December. That's when teams need to be playing their best football and we didn't do that tonight."

Center Jason Kelce said he didn't feel like the Eagles had a good week of practice. Guard Brandon Brooks felt the team's energy "tapered" during the game.

"We didn't execute. We didn't come out with the fire that we had in past games. Just wasn't a good performance offensively today," said Brooks. "Definitely a wake-up call for us. We've been winning a bunch of games, feeling good and come out here and play how we played, definitely a wake-up call."

What you need to know in the NFL

• Statistics

• Scoreboard

• 2017 schedule, results

• Standings

It's easy to forget just how fickle momentum can be in the NFL, especially when a team is dominating in the fashion that the Eagles had been during their nine-game win streak. Carson Wentz was playing as well as anyone in the league, Pederson was pushing all the right buttons and the defense was firing on all cylinders. On Sunday, things got off track. Wentz fumbled away possession near the Seattle goal line and, a couple spectacular plays aside, labored his way through this one. The offensive approach seemed conservative and counter to this team's personality. The defense yielded three touchdowns on as many red-zone trips.

A blip is fine, but with the season now approaching the final turn, Philly can't afford to make this a trend.

As Wilson said postgame, hitting your stride in December is "what championship teams do." The Eagles will carry that reinforced lesson with them as they turn the page to the Rams.

"We will be fine. The guys in this locker room are all mature," said Wentz. "We're all frustrated about this one, but we're not too worried."