By Simon Evans
MIAMI (Reuters) - The Indianapolis Colts and Pittsburgh Steelers, two of the National Football League's (NFL) powerhouses in recent years, suffered big losses on the opening Sunday of the 2011 season.
The Colts felt the absence of injured quarterback Peyton Manning instantly and brutally as they were crushed 34-7 by the Houston Texans.
The Steelers had starting quarterback Ben Roethlisberger on the field but he had a nightmare game with three interceptions as his team turned over the ball a team-record seven times in a 35-7 loss to the Baltimore Ravens.
Five of the last six Super Bowls have featured the Colts or the Steelers but there is suddenly the hint of an end of an era and it would take a brave gambler to put money on either side reaching the championship game based on what each served up on an emotional Sunday.
Stadiums around the league marked the 10th anniversary of the September 11 attacks with stirring national anthems and displays of patriotism before kick-off.
The opening games produced some other surprises with the Atlanta Falcons, a popular choice with pundits this season, falling 30-12 to the Chicago Bears.
The Buffalo Bills, who have not made the post-season since 1999, crushed the Kansas City Chiefs 41-7 with quarterback Ryan Fitzpatrick throwing four touchdowns.
Manning's run of 227 consecutive starts came to an end as he did not travel to Houston as he recovers from a third neck surgery that could leave him on the sidelines for a significant part of the season.
In place of the four-time most valuable player, the Colts went with Kerry Collins, a 38-year-old who had retired from the game in July, and the veteran struggled to impose himself in his Indianapolis debut.
The Colts were battered in the first half, falling into a 34-0 down at halftime against a Texans team playing without their elite running back Arian Foster.
Houston quarterback Matt Schaub threw for 220 yards and one touchdown while Ben Tate rushed for 116 yards and a touchdown.
Collins, who went 16-for-31 for 197 yards and a touchdown, never looked at ease in a poor performance, albeit in difficult circumstances, for the former Tennessee quarterback.
The Colts quarterback was sacked three times and produced two fumbles which set up touchdowns for the Texans.
But the problems were not just at quarterback as the Colts defense struggled against both the run and the pass.
Turnovers, particularly interceptions from Roethlisberger, played a major part in the Steelers' Super Bowl loss to Green Bay in February and, to the annoyance of head coach Mike Tomlin, that sloppiness carried into the new campaign.
Pittsburgh had beaten the Ravens in the second round of the playoffs last season but it was a very different game this time around with Roethlisberger going 22-for-41 for 280 yards and three interceptions and two fumbles.
Ravens quarterback Joe Flacco threw for 224 yards and three touchdowns but there were some outstanding displays from the always-strong Baltimore defense -- Ed Reed making two interceptions and Ray Lewis one.
The Philadelphia Eagles made a positive start with Michael Vick throwing two touchdowns in a 31-13 win over the St. Louis Rams and the Detroit Lions picked up their good form from the end of last season with a 27-20 triumph at Tampa Bay.
The Washington Redskins were hosting the New York Giants later on Sunday while the Dallas Cowboys are on the road against the New York Jets.
(Editing by Frank Pingue)