LANDOVER, Md. - Even the margin of victory reminded the playoff-bound Washington Redskins of Sean Taylor.

“I was on the sideline and guys were talking about the score, and then it hit me — we won by 21,” veteran left tackle Chris Samuels said. “I came in the locker room and I yelled it out, and immediately I just kind of broke down in tears. Because I miss Sean, you know.”

From disarray and heartache to confidence and dominance, the Redskins will enter the playoffs as the hottest team in the NFC after Sunday’s 27-6 win over the Dallas Cowboys.

And with the hottest quarterback. And maybe the hottest running back. And with a defense coming off a game in which it allowed exactly 1 yard rushing.

And, perhaps most importantly, on a mission for the teammate who wore No. 21. It’s been four weeks since the Redskins attended the funeral of their best defensive player, and they haven’t lost since.

“Win for Sean” was as strong Sunday as it was when the four-game winning streak began Dec. 6, reinforced by everything from the fiery speech given by kick returner Rock Cartwright on the field before the game to the white “21” on the front of the black baseball cap worn by coach Joe Gibbs at his postgame news conference.

“Play for the guy who’s on your jersey — the guy who’s not here, who should be here,” Cartwright said he told his teammates. “We know how he played the game. That’s why I think guys came out and played so hard.”

The Redskins (9-7) will travel to Seattle on Saturday for a 4:30 p.m. game, a rematch of a 2005 division playoff won 20-10 by the Seahawks. Washington will be riding the longest current winning streak in the NFC, including three straight victories by double digits. It’s a remarkable renaissance for a team that stayed afloat with close, ugly games before losing four straight, the last defeat coming the day before Taylor’s funeral.

“To think four weeks ago, where we were, and where we are tonight, it was a great experience and a great ride,” said Gibbs, who has quieted doubters with perhaps the best performance of his Hall of Fame career. “To get in the playoffs was a dream of ours, and four weeks ago, obviously everybody would have said, ’You know, it looks next to impossible.”’

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Sunday’s game ultimately turned out to be irrelevant — other than to serve as a possible preview of a postseason game two weeks from now. Minnesota lost 22-19 to Denver and New Orleans fell 33-25 to Chicago, giving Washington the two out-of-town results it needed to make the postseason without having to beat the Cowboys.

But beat the Cowboys they did, albeit a Dallas team that rested anyone who was questionable with an injury because it had clinched home-field advantage throughout the playoffs. Still, the Cowboys played their healthy starters most of the game and were trailing 20-3 when quarterback Tony Romo was pulled in the third quarter.

“The word for us was uninspired. It shows when one team is fired up to play and one team isn’t,” coach Wade Phillips said. “Basically, I didn’t get our team ready to play.”

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The Cowboys (13-3), who will have a bye next week, tried to muster any motivation they could find, but almost none of their goals were realized. They had hoped to win a 14th regular-season game for the first time in franchise history. Jason Witten caught only two passes, falling four short of becoming the second tight end to get 100 in a season. Receiver Terry Glenn, active for the first time all season, failed to catch a pass.

Marion Barber not only finished 25 yards shy of his first 1,000-yard season, but Barber (minus-6 yards) and Julius Jones (7) combined for 1 yard — setting a new franchise record for rushing futility. The Cowboys defense allowed a 100-yard rusher for the first time this season. The offense went 0-for-11 converting third downs, and Dallas lost its season finale for the eighth straight year.

At least Romo (7-for-16 for 86 yards and an interception) set the single-season franchise record for completions (335). And four injured starters — including Terrell Owens — got extra time to heal, although Phillips said Owens would be “iffy” for the playoffs.

“We didn’t even show up on the field,” safety Roy Williams said. “We may have showed up physically, but mentally and everything else, we didn’t show up.”

Washington’s winning streak has been led by backup quarterback Todd Collins, who took over when Jason Campbell dislocated a kneecap Dec. 6. Collins, getting his first substantial playing time in 10 years, has completed 64 percent of his passes with five TDs and no interceptions.

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Clinton Portis ran for two touchdowns and had 104 yards on 25 carries Sunday. His 27 yards on four receptions gave him a career high for yards receiving in a season (389). His yards from scrimmage during the four-game winning streak: 122, 126, 124 and 131.

Former Redskins great Dexter Manley revived memories of the old days by taking the microphone and leading cheers of “We want Dallas!” from the field before kickoff. Coincidentally, those were the very words written by Taylor on an autographed photo discovered on the Internet by defensive end Phillips Daniels’ wife, a photo Daniels shared with his teammates Saturday.

“To win by 21 on this day, to get into the playoffs,” Daniels said. “Oh, man, that’s a great feeling.”

Notes: Cowboys S Keith Davis injured his left knee in the second half, but Phillips said Davis would be fine. ... There were four replay reviews in the first half. The Redskins lost all four.

NFL game stories Quick look at Week 4 games STEELERS 23, RAVENS 20, OT: Baltimore loses first game of season REDSKINS 26, COWBOYS 24: Dallas can't contain Portis in 1st loss BEARS 24, EAGLES 20: Goal-line stand boosts Chicago JETS 56, CARDINALS 35: Favre throws career-high 6 TDs BUCS 30, PACKERS 21: Ryan's 3 FGs lift Tampa CHARGERS 28, RAIDERS 18: San Diego tops rival 10th straight time BILLS 31, RAMS 14: Buffalo 4-0 for first time since 1992 CHIEFS 33, BRONCOS 19: Johnson rushes for 198 yards for K.C. BROWNS 20, BENGALS 12: Anderson throws TD TITANS 30, VIKINGS 17: Tennessee 4-0 for first time ever PANTHERS 24, FALCONS 9: Smith honors Lucas after TD JAGUARS 30, TEXANS 27, OT: Scobey kicks game winner SAINTS 31, 49ERS 17: McAlister scores first TD of year