ARLINGTON (AP) – The ball was in the end zone on the final play of the season opener for the Dallas Cowboys. Yet, a yellow flag on the field wiped out the winning touchdown.

That game-ending holding penalty at Washington three months ago set an ominous tone for the Cowboys in a season when they had Super Bowl expectations — and the opportunity to be the first team to host the championship game.

Instead of the Super Bowl at Cowboys Stadium in February, Dallas (4-9) plays its home finale Sunday against the Redskins. The Cowboys are already guaranteed a losing record for the first time in six seasons.

“There’s no question, momentum, division opponent, that kind of sets the tone for the way the season is going to go,” tight end Jason Witten said this week. “Obviously, if we had found a way to pull it out, that would have been a big step for our team.”

On the other side, Washington (5-8) didn’t exactly parlay the fortunate opening victory into a sensational season for coach Mike Shanahan’s return to the sideline and Donovan McNabb’s first year there.

The Redskins, whose only touchdown in the opener came on a mistake by Dallas, have a three-game losing streak. Their most viable remaining goal is to stay ahead of Dallas at the bottom of the NFC East and avoid a third consecutive last-place finish.

“Yeah, we’re thinking about that,” guard Kory Lichtensteiger said. “We’re looking to get back in the right column to end the year. Having a bad season is one thing, but ending the year bad is a whole other thing altogether.”

Washington has a chance to sweep the season series against the Cowboys for the first time since 2005, and only the fifth time since the division rivals started playing twice a year in 1961.

“It ain’t necessarily about not getting caught — we want to sweep ’em,” cornerback DeAngelo Hall said. “Obviously we’re down this year; they’re down this year, but definitely want some bragging rights to say we swept ’em.”

Hall scored the lone Redskins touchdown in the opener, when he helped strip running back Tashard Choice of the ball and returned it 32 yards on the final play of the first half for a 10-0 lead.

That play came after then-coach Wade Phillips decided to try to score instead of letting time run out when the Cowboys got the ball at their own 30 with 27 seconds left in the half. That is still Choice’s only career fumble, one he said this week he won’t ever forget.

Phillips was fired after a 1-7 start and offensive coordinator Jason Garrett became interim coach, the first midseason coaching change for owner Jerry Jones. The Cowboys are 3-2 since, both losses by 30-27 scores — to New Orleans and Philadelphia.

While still bitterly disappointed that another team will represent the NFC in the Super Bowl at his $1.2 billion showplace, Jones has felt better about how the Cowboys have responded under Garrett.

“I think a lot of it is a reflection of (Garrett) and the men in the room that go out there and play,” Witten said. “I think he’s done a great job of throwing it out there and allowing us to understand here’s where our expectations are and the standard and we’re not deviating off of that.”

After last week’s loss to Philadelphia to guarantee a losing record, Jones still spoke of being encouraged and made one thing clear: the Cowboys will do everything they can to win the last three games.

“Try to make every score and every down we can. It’s all important to me,” the owner said.

“The goal each week is to try to win football games. That’s what we’re going to try to do,” said Garrett, who seems likely to remain the coach after this season. “We’re going to try to put our best football forward, to that end.”

While the Cowboys still aren’t sure if Tony Romo will play again this season after he broke his collarbone on Oct. 25, Shanahan playfully dodged questions this week about whether a healthy McNabb would even start Sunday.

The Redskins coach presumably wants to keep Dallas guessing about a possible though unlikely quarterback switch to Rex Grossman over McNabb, who already has a career-high 15 interceptions. The Cowboys weren’t swayed to think that way.

“Donovan McNabb is one of the marquee players in this league and can beat you in so many different ways,” Garrett said. “We’re certainly preparing for him.”

McNabb’s final game with the Eagles was a playoff loss at Cowboys Stadium last January. In his first game with Washington, he completed 15 of 32 passes for 171 yards and led two drives that ended in field goals.

Washington is coming off a one-point loss against Tampa Bay. A botched extra point in the closing seconds made it impossible for the Redskins to finish with a winning record.

“I’m not worried about the standings, I’m worried about this game,” safety Reed Doughty said. “Our standings don’t look good anyway you want to look at it, so this game is about beating the Cowboys. We want to beat ’em.”

McNabb sees a lot of similarities in the NFC East rivals who will play their 100th regular-season game against each other. Dallas has won 59, its most against any opponent.

“They are playing a lot harder. … Offensively and defensively they, obviously, stepped up to the challenge after Wade was fired and guys have understood the circumstances,” McNabb said. “They are pretty much in the same situation that we’re all in around here. You’re trying to do whatever it takes to win games.”

(Copyright 2010 by The Associated Press. All Rights Reserved.)