ARLINGTON, Texas - The roller coaster at the Six Flags theme park is quite visible from the Dallas Cowboys' monstrosity of a home field. That ride had nothing on what was happening Sunday night inside AT&T Stadium, where the Eagles needed a win for their ninth NFC East title.

"Up and down, up and down," linebacker Mychal Kendricks said, describing the exhausting swings of momentum and emotion that didn't cease until second-year cornerback Brandon Boykin pulled in an interception that secured the Eagles' 24-22 win over the Cowboys and a Saturday night date with Drew Brees and the New Orleans Saints in a wild-card playoff game.

It was fitting that the Eagles' 10th win of the regular season would be completed by a takeaway, because that was the trademark of a defense that could give up huge chunks of yardage but still have a positive impact on the outcome of a game. A year ago, the Eagles had eight interceptions and five fumble recoveries for a league-worst 13 takeaways.

With two interceptions and a fumble recovery Sunday, the Eagles finished with 19 interceptions and 12 fumble recoveries for 31 takeaways.

"It's a huge statistic whether it's in college or pros," Eagles coach Chip Kelly said. "We were very good at it when I was at Oregon, and it was the reason we won so many games. They're really striking if you look at the numbers in our 10 wins and our six losses."

In many ways, this night in Texas seemed like a no-win situation and a must-win situation at the same time for the Eagles' defense. No matter what coordinator Bill Davis' unit did against the Cowboys, it was going to have an asterisk next to it because Kyle Orton, a veteran quarterback who had not been on the field since losing his job to Tim Tebow two seasons ago in Denver, was playing instead of Tony Romo.

That meant the Eagles' defense was expected to shut down one of the highest-scoring offenses in the NFL just as it had the week before at home against the Chicago Bears. That assuredly would allow the Eagles' offense to turn the evening into a rout.

That was the plan. The reality was entirely different.

Orton, for most of the night, was better than anybody could have anticipated. And for the second time this season, the Cowboys' porous defense was at its best against Nick Foles and the Eagles' high-powered offense. That meant in order to win, the Eagles needed the lesser of their two units to be at its best, too.

And when we look back at the game that clinched perhaps the most unlikely NFC East title in the Eagles' history, it will be the work of the defense that is most applauded for the hard-fought win over the Cowboys.

Every time the momentum needed changing, it was the defense that did it for the Eagles, with Boykin coming up with the play that will be remembered in Philadelphia for a long, long time.

After the Eagles' offense stalled deep in its own territory just after the two-minute warning, the Cowboys got the ball on their own 32-yard line in need of about 30 yards to set up a game-winning field-goal attempt.

Instead, Boykin made sure the Cowboys didn't get a single yard. Orton's pass on first down was behind receiver Miles Austin, and Boykin secured it for the interception that finally sealed the game. It was the second interception and third takeaway of the game for the defense.

"I knew they were trying to get into that hole in the middle because they were getting a lot of yards there and I just undercut [Austin] at the last second," Boykin said. "I've never had a bigger play in the closing part of the game with so much on the line. It's a complete blessing."

Kendricks was also in the middle of the momentum-changing evening, forcing a fumble to snuff an early Dallas scoring threat and coming up with a huge interception that led to an Eagles touchdown shortly before halftime.

The other huge defensive plays were provided by linebacker Connor Barwin, who knocked down a fourth-and-1 pass attempt by Orton at the Eagles' 40-yard line in the fourth quarter, and cornerback Cary Williams, who denied Dez Bryant on an attempt to catch a two-point conversion that would have tied the game in the final quarter. Barwin's play led to the Eagles' final touchdown.

It was by no means a work of art by Davis' defense. Much-maligned safety Patrick Chung was burned for a touchdown late in the game when he couldn't tackle Bryant on a pass over the middle, and Orton finished 30 for 46 for 358 yards.

But it was good enough on this evening even if it might not be good enough to beat Brees and the Saints Saturday night.

"It wasn't our best defensive effort," Barwin said. "But some guys came up with some huge plays when we needed to get off the field . . . but we've got to play better next week; I know that."

The first significant play by the defense came on the game's opening series. After giving up huge chunks of yards and allowing Orton to get in an early groove by completing his first three passes, Kendricks jarred the ball loose from running back DeMarco Murray and it was recovered by Bradley Fletcher at the Eagles' 23-yard line.

The offense countered with a field goal to give the Eagles a 3-0 lead.

It was the first time Kendricks and the defense altered the game's momentum. It would not be the last.

It appeared as if Dallas was primed to take the lead or at least tie the game just after the two-minute warning in the first half when Kendricks intercepted an Orton pass behind tight end Jason Witten and returned it to the Dallas 49-yard line.

That turnover set up the Eagles' second touchdown of the game that made the score 17-7. It was indicative of how the defense played the entire season.