By Steve Ginsburg

LANDOVER, Maryland (Reuters) - The Washington Redskins opened the highly anticipated Mike Shanahan era in style Sunday night by slipping past the Dallas Cowboys 13-7 in the season-opener for both teams.

With new coach Shanahan barking orders from the sidelines, the Redskins snapped a three-game losing streak against their bitter rivals in the NFC East largely courtesy of a controversial late holding call.

"You've got to find a way to win in this business," said Shanahan, a two-time Super Bowl champion with the Denver Broncos.

"A lot of teams are very close. You've got to find a way to get it done. And that's what our football team did today."

The Redskins looked like losers when Dallas quarterback Tony Romo found Roy Williams in the corner of the end zone for an apparent 13-yard scoring strike as time expired.

Cowboys right tackle Alex Barron was cited for holding Redskins linebacker Brian Orakpo, however, and that nullified the potentially game-winning touchdown and ended the game.

"I've never seen that happen," said Cowboys coach Wade Phillips. "We score a touchdown and then get a penalty and the game is over.

"I thought they grabbed our guys several times trying to get to our quarterback but I guess they didn't."

Romo, who completed 31 of 47 passes for 282 yards and one touchdown, said the finish was hard to take.

"I thought we won and then 10 or 15 yards after running away I noticed people weren't coming out on to the field," he said. "It's hard to swallow."

Washington's touchdown came gift-wrapped on the final play of the first half when Romo hit Tashard Choice on a short pass but the running back was stripped of the ball by DeAngelo Hall.

The cornerback rambled 32 yards for the score to give the Redskins a 10-0 lead, somersaulting in celebration to the roars of nearly 91,000 fans at FedEx Field.

"I was able to get my hands on the ball, break it out and pick it up and score," said Hall. "My intention the whole time was to rake the ball out."

Quarterback Donovan McNabb, a six-time Pro Bowler playing his first game with the Redskins after 11 seasons in Philadelphia, hit 15 of 32 passes for 171 yards.

The Cowboys outgained the Redskins by 380 to 250 yards, however, and McNabb conceded the offence had sputtered for most of the evening.

"Offensively, we just didn't get the job done," he said. "We made enough plays, drove the ball, and got in the red zone. We just have to finish it. That's discouraging for us."

Romo had hit Miles Austin for a four-yard touchdown late in the third quarter to trim Washington's lead to 10-7 before Graham Gano made it 13-7 with a 49-yard field goal with 1:50 remaining.

Shanahan, who replaced Jim Zorn after last season's 4-12 record, was thankful to walk away with the win any which way.

"It's very special because Dallas is a very good football team," he said. "We didn't win a division game last year. I thought it would be a great way to start off this year and fortunately we found a way to get it done."

(Editing by Nick Mulvenney)