Aaron Rodgers threw for two touchdown passes and Nick Collins returned an interception for another score as the Green Bay Packers took a 21-10 lead over Pittsburgh at halftime of Super Bowl 45.
Ben Roethlisberger got off to a shaky start before connecting with receiver Hines Ward for an eight yard touchdown late in the second quarter but the first half was dominated by the Packers.
Packers safety Collins intercepted a soft pass from Roethlisberger and returned it 37 yards for a touchdown to give Green Bay a 14-0 lead with 3:34 left in the first quarter.
The Packers won the pre-game coin toss but elected to let the Steelers' offence have the ball first.
By the time the opening kickoff took place Cowboys Stadium was a sea of yellow with Steelers fans waving Terrible Towels mixed in with the yellow Cheesehead headgear popular with Green Bay fans.
The crowd seemed to be split down the middle and as soon as a "Go Pack Go" chant would start up it would be drowned out by a "Go Steelers Go" and vice versa.
Sunday's game at Cowboys Stadium marks the first Super Bowl meeting between two of the NFL's most stories franchises the Steelers and Packers, who now have 15 appearances in the showpiece between them.
A who's who of the American celebrity circles were also on hand for the game, including actor Michael Douglas and his wife Catherine Zetta Jones, singer Kid Rock and New York Yankees baseball star Alex Rodriguez.
The game was expected to be the most watched event in US television history. Even US President Barack Obama got into the spirit by hosting lavish Super Bowl party for about a 100 VIPs and dignitaries at the White House.