They taunted the Redskins' crowd during pre-game introductions and started a skirmish during warm-ups as Washington was headed back to its locker room.
And throughout the game, they showed the confidence of a team that had won the five previous meetings with the Redskins.
No. 6, though, may have been the biggest surprise - a 27-21 victory before 82,331 at Fed ExField in front of a national television audience in what many thought would be a Super Bowl year for the Redskins.
"They ran on our side of the field," linebacker LaVar Arrington said. "They had that 'We're better than you' attitude. And we let them get the best of us tonight."
Especially Randall Cunningham. The 37-year-old castoff, filling in for quarterback Troy Aikman, threw two touchdown passes to spark the Dallas upset.
Cunningham had a 76-yarder to Chris Warren and a 16-yarder to Jackie Harris to drop the Redskins to 1-2, the same record as the Cowboys.
For Dallas, a 10-point underdog after allowing 73 points in losses to Philadelphia and Arizona, it not only was its first victory but new coach Dave Campo's first win.
The Redskins' offense played its first game without wide receiver Michael Westbrook, who suffered a season-ending knee injury last week against Detroit.
They could have used him late in the fourth quater when they were down 24-21. Quarterback Brad Johnson threw a crucial interception right into the arms of safety Izell Reese. The Cowboys turned that into a 38-yard Tim Seder field goal with just under two minutes left.
Johnson, who completed 30 of 48 for 241 yards, tried to rally the team one last time, but the game ended with him lying on the ground after a Cowboys sack.
He can now expect a ton of criticism and cry for backup quarterback Jeff George to take over.
"It is always easy to point at the quarterback," Redskins coach Norv Turner said. "When you are struggling on offense you have to realize there are 11 guys out there on the field. We are looking at every possibility of why we are not playing as well on offense as we are capable of playing."
Johnson added: "We expect to play better. Right now we are not accomplishing that. Tonight we put ourselves in bad situations."
Asked if he might replace Johnson with George, Turner replied: "That's not a question I'm going to deal with now."
Dallas led 14-7 at halftime and continued to control the ball on the first possession of the second half, moving down to the Redskins' 14 before settling for a 31-yard field goal to go up 17-7.
Washington's defense got the team jump-started midway through the third quarter.
Redskins strong safety Sam Shade atoned for giving up an earlier touchdown by intercepting Cunningham on the Cowboys' 23. Five Stephen Davis runs later, the Redskins cut the lead to 17-14.
But in the final quarter, the Redskins did things that losing teams do. Tackle Andy Heck, who wasn't in the game at the time, committed a bad personal foul, shoving a Cowboys player on the Redskins' sideline. That play came after a Davis 5-yard run, and turned a third-and-five into a third-and-20.
The Redskins eventually punted. Tommy Barnhardt pinned the Cowboys back to their own 20, but they escaped with a 43-yard Cunningham-to-Rocket Ismail pass. Cunningham scrambled to his left before tossing a pass clear across the field and hitting Ismail.
Two plays later, Cunningham, pivoting to his left again, found tight end Harris for a 16-yard touchdown to put the Cowboys up 24-14 with 9:19 left.
The Redskins did answer on their next possession. Johnson led a nine-play drive that ended in a 7-yard touchdown pass to fullback Mike Sellers with five minutes left.
But it wasn't enough.
Washington broke on top, taking a 7-0 lead on Stephen Davis' 7-yard touchdown run. The score was set up by a reverse on a 54-yard punt return. Deion Sanders fielded the punt, cut to his left and handed it to Champ Bailey, who raced down the sideline to the Cowboys' 33.
Things went downhill after that.
Cunningham bobbled the snap on the ensuing possession but recovered to find a wide-open Warren down the sideline for a 76-yard touchdown to tie the game at 7.
Warren beat Shade, who got caught looking at Cunningham in the backfield.
Dallas tackle Leon Lett caused a fumble on the Redskins' next possession while sacking Johnson at the Cowboys' 46. An eight-play, 49-yard touchdown drive was capped off by a 3-yard Emmitt Smith run.
The schedule doesn't get any easier for the Redskins. They face the undefeated New York Giants at the Meadowlands next Sunday night, then play 3-0 Tampa Bay the following Sunday.
"We can't worry about who we play," Turner said. "We just have to play better."
NOTES: Former Redskins coach Joe Gibbs made a rare appearance at FedEx Field last night. Gibbs, Art Monk and Dexter Manley were inducted into the Redskins' Ring of Fame. Gibbs, who coached the team to three Super Bowl victories from 1981 to '92, said Redskins owner Daniel M. Snyder did contact him a while back about coming back to the organization. ... The Redskins signed kicker Michael Husted and released wide receiver Derrius Thompson.
The Associated Press contributed to this article.