Donovan McNabb scrambled, buying time again in an attempt to find the big play that had mostly eluded the Eagles all night, but an unheralded rookie from Oregon State caught him from behind.

It was the fourth, and most important, Dallas sack of the night in the 20-16 Cowboys' victory. And Victor Butler made the play on another successful pass rush, which had consistently thrown off a potent Eagles offense.

"McNabb might still be running if he doesn't make that tackle," linebacker Keith Brooking said.

Dallas' pass rush forced three first-half sacks and put a largely ineffective McNabb into a perpetual scramble. In the second half, McNabb withstood the pressure to make a few plays, but Dallas held on, with Butler's play forcing a field goal instead of a touchdown.

The Cowboys applied the pressure with hopes of containing an offense that has shown a propensity for big plays throughout the season. In the first half, McNabb's longest completion was 23 yards to Jason Avant on third and 6 to start the second quarter.

On the first drive of the third quarter, McNabb scrambled with success. Two plays before hitting Brent Celek on a scrambled, broken play for Philadelphia's first touchdown, McNabb was flushed out of the pocket again. Still with time to spare, he found LeSean McCoy for a 45-yard catch-and-run, the team's longest play of the game.

And that was about it.

"We kept them from having big plays," Dallas coach Wade Phillips said, "except for the one screen pass."

Keeping McNabb off-balance and disrupting his timing was the key for the Cowboys defense. Entering the game, Dallas hadn't put up astounding sack numbers (tied for 10th in the NFC). And the two interceptions against McNabb were half the Cowboys' total for the seven previous games.

The Eagles attempted more screen passes than normal in an attempt to slow down the pressure. They didn't make a huge difference. McNabb finished 16 for 30 for 227 yards, the one touchdown, and two interceptions.

"We knew they relied on big plays," linebacker Bradie James said. "Without [Brian] Westbrook, they couldn't nickel-and-dime us all the way down the field. They needed a big play. If we could just contain the big play, our rush was just pinning their ears back."

At one point, the Dallas pressure forced McNabb on a scramble nearly parallel to the 30-yard line. He had three defenders tracking him, and McNabb didn't even attempt to turn upfield, instead running out of bounds for a 1-yard loss.

"We didn't do anything differently," Brooking said. "It was a lot of pressure. We were in his face a lot. You have to do that. If you let that guy sit back there, he'll pick you apart. That was the key to our game."

Contact staff writer Matt Gelb

at 215-854-2928 or mgelb@phillynews.com.