Washington (AFP) - The Seattle Seahawks hope their sensational Super Bowl victory heralds an era of dominance as they begin their title defence on Thursday at home against Green Bay.
The NFL's 2014 season opener sends the defensive-minded Seahawks against a Packers squad seen as their top rival for National Conference supremacy in the fight to reach Super Bowl 49 next February in Arizona.
"One championship is special. Two is historic," Seahawks linebacker Bobby Wagner said. "Three is a dynasty."
Not since the New England Patriots in 2004 and 2005 has a team won the Super Bowl in back-to-back years and not since the Dallas Cowboys in 1993 and 1994 has a club from the National Conference won consecutive NFL crowns.
"We're just getting warmed up," Seahawks coach Pete Carroll said last February at the team's victory parade after Seattle routed Denver 43-8 in the Super Bowl for the team's first NFL title.
Referees have cracked down on illegal contact and defensive holding in pre-season games, a move some see as aimed at Seattle's hard-hitting "Legion of Boom" defensive unit.
The league also fined and penalized the club for violating rules against contact in off-season workouts, signs of aggressiveness and intensity already building in Seahawks players.
"We tried to do things better than last year, with the same tone and same thought," Carroll said. "We're always competing here. That's how we do this. We're trying to do things exactly right. We are trying to do things the best you can."
Seahawks' defenders conceded the fewest points in the NFL over the past two seasons, cornerback Richard Sherman and safety Earl Thomas keys to an aggressive unit that humbles opponents, including Denver star quarterback Payton Manning and the highest-scoring attack in NFL history in last February's Super Bowl.
"This group can be a special team," safety Kam Chancellor said. "I think the sky is the limit for this team. We're still hungry."
"Our big thing with the offense is just to get in tune with the defense," Harvin said. "They have shut people down. They have carried us at times. We just want to make our team more balanced."
- Packers ready for another run -
Green Bay mixes young talent with veteran leadership and experience to make the Packers a threat for the crown once again despite losing star defensive lineman B.J. Raji for the season with a torn biceps.
The Packers and New England have reached the playoffs for five years in a row, the longest active such streaks, and Green Bay quarterback Aaron Rodgers led his team to the Super Bowl title in 2011.
"I feel like we're just getting ready to have our best run," Packers coach Mike McCarthy said. "If we stay healthy I think we will at least have a shot at it."
Another championship contender will be San Francisco, with quarterback Colin Kaepernick signing a six-year contract extension that brought $61 million guaranteed and as much as $126 million, especially if he can bring the 49ers their first Super Bowl triumph since 1995.
"That's your goal as a player, to win a Super Bowl every year," Kaepernick said. "Granted that's not realistic, to win it every single year, but that's what your goal is."
The 49ers lost to Baltimore in the 2013 Super Bowl and to Seattle in last season's National Conference final.
In the American Conference, Denver will again be a title threat with Manning at the helm and New England, with 37-year-old quarterback Tom Brady sparking the attack, will be a contender for the crown as well, having lost the Super Bowl in 2008 and 2012 after winning three in four years from 2002 to 2005.
Both the Patriots and Broncos have bolstered their defenses, taking a page from the Seahawks, as they try to hold off improving Indianapolis, led by young quarterback Andrew Luck, and perennial contenders Pittsburgh and Baltimore, whose defenses have played well enough to offset scoring struggles.