The Steelers were up 10-7, but Arizona had the ball on the Steeler’s 2 yard line with 18 seconds remaining in the first half. The Steeler’s defense had blitz written all over them and blitz they did forcing Cardinal’s quarterback Kurt Warner to throw way quicker than he would have liked to. Steeler linebacker James Harrison faked the blitz and hung back only to see the errant pass come in his direction. He picked it off and seeing nothing but daylight headed straight for glory. When the Cardinal players finally caught up to him, all they could do was knock him into the end zone.
Harrison laid down in the end zone for a while the photographers did their business. It probably took him a little while to realize that he just scored on the longest play in Super Bowl history. Running 100 yards and giving the Steelers a 17-7 halftime lead. After a Cardinal comeback, the Steelers went on to win the game, 27-23, with a spectacular leaping catch in the end zone by Steeler receiver Santonio Holmes from QB Ben Roethlisberger.
The interception became known in the sports archives as the “Immaculate Interception”. See it here.