Dallas Cowboys Seattle Seahawks
The Dallas Cowboys are the first team to beat the defending Super Bowl champs in Seattle this season. Reuters/Steven Bisig-USA TODAY Sports

The Seattle Seahawks are unbeatable at home, or so that’s what most NFL fans thought entering Week 6. The Dallas Cowboys proved otherwise, beating the defending Super Bowl champs in front of a crowd over 68,000 fans that is known for providing the league’s best home-field advantage.

Seattle’s fan base is so rabid that the crowd at CenturyLink Field has its own No.12 jersey, which ranks 10th among all NFL jersey sales. Going on the road and beating the winners of Super Bowl XLVIII is no small feat, and doing so has made the Cowboys one of the favorites in the NFC.

The Cowboys' victory might be the most impressive of the 2014 NFL season, but winning on the home field of the defending Super Bowl champs doesn’t guarantee future success. In the last 10 seasons, 18 teams have accomplished what the Cowboys did on Sunday, and none have gone on to win the Super Bowl in the same year.

The only team in last decade to beat the defending champs on their home field and reach the Super Bowl was the 16-0 New England Patriots of 2007, who were upset by the New York Giants in the title game. Two other teams, including last year’s Patriots, reached the conference championship game.

Beating the defending champs on the road doesn’t even mean much in terms of making the playoffs. Since 2004, half the teams that defeated the previous year’s Super Bowl winner at home went on to miss the postseason.

The Cowboys know all too well that they have a lot of work to do, despite their win in Seattle. In the 2012 season opener, Dallas beat the defending champion Giants at MetLife Stadium. Tony Romo and Co. went on to lose eight of their next 15 games, finishing in third place and having to watch the playoffs from home.

Losing to the defending champs is actually a better indicator of future success than beating the previous year’s Super Bowl winner. Four Super Bowl champs since 2005 faced the defending champs in the regular season. Only the 2013 Baltimore Ravens were victorious.

The Week 6 victory, though, might be more significant than one’s in recent years. Four of the last 10 Super Bowl winners didn’t reach the postseason the following year, including the 2012 Giants. The Seahawks are still considered one of the best teams in the NFL, having already beaten the Denver Broncos and Green Bay Packers.

Since 2012, the Seahawks have been dominant in Seattle, losing just once prior to Sunday’s contest with the Cowboys. Seattle went 7-1 at home during last year’s Super Bowl season, defeating opponents by an average of nearly 19 points per game.

At 5-1 the Cowboys are tied for first place in the NFC East, sharing the NFL’s best record with the Philadelphia Eagles and San Diego Chargers. Dallas began the season as 66-to-1 favorites to win the Super Bowl, but are now 14/1.