No more a preseason favorite than the 5-1 San Diego Chargers, the shift in thinking that the Dallas Cowboys are legitimate contenders was sudden and established the same way the Chargers earned notice — beating the Seattle Seahawks.

And that in Seattle, 30-23. After two losses, the defending Super Bowl champions are doing some serious self-evaluation.

Four games over .500 for the first time since 2009, the Cowboys continue to build a convincing argument that this team can be a real contender, the latest exhibit being Sunday’s win at Seattle, where the Seahawks are 19-2 since the start of 2012.

“It’s a big win,” tight end Jason Witten said. “Hopefully we can build on this.”

The reasons to buy in are there. Dallas dominated Sunday’s game. If not for a series of special teams gaffes, this is a trophy-grade blowout of the reigning World Champions. The offensive line isn’t good, it’s great. DeMarco Murray, running for a contract with free agency months away, leads the NFL in rushing; Rod Marinelli’s no-name defense made Russell Wilson look human and stopped Percy Harvin and Marshawn Lynch with a diverse scheme that kept Seattle play-caller Darrell Bevell guessing.

The most compelling reason to be optimistic about the Cowboys going forward with all the momentum gathered in coach Jason Garrett’s first five-game winning streak: Scott Linehan and the schedule.

“We found an identity,” said Witten. “Even when we’re behind. It’s been a winning formula for us. But we know there’s a lot of football left.”

Take a peek at what’s next for the Cowboys. Five games before the Thanksgiving Day date with the 2013 NFC East champion Eagles (5-1) bring two games with the Giants (3-3), a Monday Night Football visit to Washington (1-5), the Arizona Cardinals (4-1) and a swing through Jacksonville (0-6).

After three consecutive 8-8 seasons, Dallas might have just finally found the right balance with its coaching staff.

Linehan has worked wonders for the Cowboys’ offense, which wobbled under Garrett’s control unable to find the run-first gear that best suits their personnel. In six games, the Cowboys have 200 rushing attempts for 969 yards.

In 2013: 336-1,504.

In 2012: 355-1,265.

Murray’s workload could become worrisome. On a start matched in production only by Jim Brown, Murray is on pace to set a single-season record with more than 416 carries (Larry Johnson, Chiefs, 2006). Owner Jerry Jones paid lip service to the need to divvy up carries, and Linehan found five carries for Joseph Randle. He rewarded the team with 52 yards — including a 38-yarder — plus four catches for 48 yards.

Dallas is winning games it lost in past years, including two final-drive wins in a row.

“Any other time we would have blinked. We probably would have folded and gave up. But we didn’t do that,” said Cowboys wide receiver Dez Bryant.

Three of the next five are on the road for the Seahawks, who then play the 49ers twice in a three-week span.

Dallas and San Diego took down the champs by building a lead and taking away the running game that sets the tone for the entire team’s smashmouth mentality. At least one ring-wearing veteran pointed to a level of complacency that coach Pete Carroll guarded against starting with his day-after Super Bowl press conference, when he said “‘this isn’t about just one trophy.”

“We have to quit BS-ing ourselves,” wide receiver Doug Baldwin said. “We’ve got to be real with ourselves. When we get in the meeting room, we’ve got to actually pay attention to things and not blow smoke up our tails that everything’s going to be all right. Things aren’t going right. Pay attention to things that we’re not doing right and correct them.”

WHAT WE LEARNED WEEK 6 HIGHLIGHTS:

Arizona 30, Washington 20

–Arizona is atop the NFC West with Carson Palmer back at the controls. Quarterback Carson Palmer was not sacked or intercepted and felt fine after flinging 44 passes in a 30-20 win over Washington that pushed the Cardinals into sole ownership of the top spot in arguably the best division in the NFL.

First-place Arizona (4-1) holds a one-game lead over the defending Super Bowl champion Seattle Seahawks and the San Francisco 49ers in the NFC West.

“Today I had a really good idea (that I would play),” Palmer said. “I went through the whole week and threw very little on Wednesday, very little on Thursday and then felt pretty good on Friday and took about a quarter of the reps in practice and actually got in some 11-on-11 situations and seven-on-seven, and it felt good. It felt good Saturday, and it felt really good today.”

Carolina 37, Cincinnati 37

–Carolina Panthers quarterback Cam Newton found his legs. In a 37-37 tie at Cincinnati, Newton showed his left ankle is not an issue with 17 carries for 107 yards.

“He was phenomenal,” coach Ron Rivera said. “He’s pretty close to being who he is.”

It was the first time since offseason surgery Newton moved easily in every direction and didn’t show pause when opportunities to run were presented.

“He had a pretty good day, huh?” tight end Greg Olsen said.

Denver 31, New York Jets 17

–Quarterback Peyton Manning and the Denver Broncos are on the doorstep of history. Manning tossed three more touchdowns Sunday to run his total to 506 career touchdown passes, two shy of Brett Favre’s all-time NFL record.

The milestone touchdown pass will almost certainly come in Denver, where the Broncos host the San Francisco 49ers Sunday and the San Diego Chargers four days later (Oct. 23).

Manning, already the NFL career leader in passing yards, pass attempts and completions, said he’s not focused on adding the touchdown record to his resume.

“I don’t know if any of them are big for me, especially in the middle of a season — we’re trying to win football games,” Manning said. “Two games in five days coming up — that’s plenty to think about.”

San Diego 31, Oakland 28

–In a heart-stopper in Oakland, the San Diego Chargers showed good teams find ways to win.

Quarterback Derek Carr’s fourth touchdown pass gave the Raiders a 28-21 lead with 10 minutes to play.

Chargers running back Branden Oliver, an undrafted rookie out of Buffalo, scored on a 1-yard run with 1:56 left to play, giving the Chargers the lead. San Diego sealed the win when rookie cornerback Jason Verrett, a first-round draft pick from TCU, intercepted Carr’s deep strike intended for wide receiver Brice Butler on second-and-1 from the Chargers’ 44 with just over a minute to play.

“When it came down to it in crunch time, both sides stepped up,” Chargers quarterback Philip Rivers said. “I think it was big to win like this.”

Detroit 17, Minnesota 3

–Detroit’s defense can be a destructive, championship-level group … if it’s kicking game doesn’t kill the Lions first. Detroit’s defense was animalistic, sacking Minnesota Vikings rookie quarterback Teddy Bridgewater eight times, picking him off on three occasions and holding the Vikings to 212 total yards.

Vikings coach Mike Zimmer said, “They kicked out butt. We physically got beat.”

Kicker Matt Prater, a Pro Bowler with the Denver Broncos last season, was signed on Tuesday after Alex Henery missed three kicks in a 14-13 loss to Buffalo last week. Prater missed a pair of kicks himself in his Lions debut Sunday, missing wide left on a 50-yarder in the second quarter and blasting one off the left upright on a 44-yard try in the third quarter.

“We feel good about him. We have all the confidence in the world,” Lions coach Jim Caldwell said. Prater did hit a 52-yarder with one second remaining in the first half.

Baltimore 48, Tampa Bay 17

–Tampa Bay’s upgrades are not paying off. Changes from the top (general manager and coach) and across the board, including big-money deals for defensive end Michael Johnson, cornerback Alterraun Verner and quarterback Josh McCown have not paid dividends for coach Lovie Smith and the Buccaneers. The Ravens blew the doors off Tampa’s cover-2 zone in the first quarter, when quarterback Joe Flacco had four touchdown passes.

“We were talking about, at that point, ‘Shoot, we’re almost on pace for 16 touchdowns,'” Flacco joked afterward.

Tampa Bay gave up 48 points, and the Buccaneers defense has surrendered 34 points per game.

“I think we took a step back. I’m just being honest, being one of the leaders,” Bucs defensive tackle Gerald McCoy said. “We’re just not as good as we should be at this point. There is no secret formula why it happened. We’re just not where we should be.”

New England 37, Buffalo 22

–There were positives and negatives for the New England Patriots. Quarterback Tom Brady was unstoppable against the Buffalo Bills yet again, with 361 yards and four touchdowns in a 37-22 whipping at Ralph Wilson Stadium. Brady is now 23-2 in his career facing Buffalo. In the Patriots’ past two victories, Brady has thrown for 653 yards, six touchdowns and no interceptions. On Sunday, he became the fifth player in NFL history with 60 career 300-yard passing games.

“Just being around him gives you confidence,” wide receiver Brian Tyms said.

Yet, the victory was “a little bit bittersweet,” Patriots coach Bill Belichick said. Starting linebacker Jerod Mayo was carted off the field in the first half with a knee injury. Running back Stevan Ridley also went out with a knee injury, and left guard Dan Connolly was knocked out with a head injury.

Chicago 27, Atlanta 13

–Atlanta is becoming an afterthought thanks to a defense that cannot get off the field. Ranked 28th against the run, the Chicago Bears gouged the Falcons in every way possible. Receivers Brandon Marshall and Alshon Jeffery each went over 100 yards in receiving, and running back Matt Forte finished with 157 total yards. Few teams can stack up against that trio of weapons if quarterback Jay Cutler doesn’t turn it over, but the Falcons made life easy on the Bears.

“We’ve played very inconsistently on defense throughout the entire season, and we haven’t played nearly up to our potential on the offensive side of the football either,” Atlanta coach Mike Smith said. “I don’t think anything is off the table in terms of what we’ve got to get done. These are the guys that we have on our football team. We have to coach them better. They have to play better.”

Tennessee 16, Jacksonville 14

–The Blake Bortles project in Jacksonville is coming along slowly. The rookie quarterback has seven interceptions against just four touchdowns in his first 143 attempts. He showed some positive signs on Sunday. Bortles started hot out of the gate, hitting a number of receivers with short tosses early in the game and then led tight end Clay Harbor on a nice 59-yard throw down the right sideline.

Bortles must learn to get rid of the ball faster — even though he showed nice pocket presence, the Titans sacked him six times. One of his chief antagonists, Titans defensive tackle Jurrell Casey, was impressed.

“He did a great job today. I can’t knock him, he did a heck of a job getting out of the way of pressure, getting them back into the game at the end, he did a great job,” Casey said. “He’s got a lot of work to do, but I think he’s going to be a top quarterback one of these days.

Philadelphia 27, New York Giants 0

–This game proved the value of an offensive line, which was reflected in the score.

For all that was made of LeSean McCoy’s breakout game Sunday night (149 yards on 22 carries), more important for the Eagles are signs the offensive line is finally holding its own. The line was hit hard by injuries and two starters — left guard Evan Mathis and center Jason Kelce — are still sidelined.

However, the Eagles have been bolstered by the return of right Lane Johnson, who missed the first four games after he was suspended for testing positive for a performance-enhancing drug. Also, the two young players who replaced Mathis and Kelce, Matt Tobin and David Molk, respectively, are improving.

In direct contrast, the Giants added skill players such as running back Rashad Jennings and rookie wide receiver Odell Beckham Jr. this season, but that won’t mean much if the line can’t do a better job protecting quarterback Eli Manning than it did Sunday night. Manning was under duress much of the night and was sacked four times in the first half as the Eagles built a 20-0 lead. Giants quarterbacks were sacked a total of eight times in the game, with offensive tackle Justin Pugh giving up three of them.

They were even more upset that wide Victor Cruz was lost for the season when he blew out the Patellar tendon in his right knee in a non-contact injury just as it appeared he might catch a pass for the Giants’ only score of the game.

Some content for this column was contributed by Sports Xchange correspondents covering each game.