Green Bay and Pittsburgh punched their tickets to the Super Bowl, building substantial first-half leads then surviving late scares before holding on to win their NFL semi-final games.
The Packers advanced to their first Super Bowl in 13 years with a 21-14 victory over long-time rival Chicago, who could not overcome a quarterback crisis in the NFC championship game.
"This is a dream come true, incredible feeling. I am at a loss for words," Packers quarterback Aaron Rodgers said. "We just had enough points on offense and B.J. had an incredible touchdown."
B.J. Raji scored on a 18-yard interception return and Rodgers ran for another touchdown as the Packers held off a late charge by Chicago to reach the Super Bowl 45.
Raji's interception run to the end zone put the Packers up 21-7 in the fourth quarter and provided the deciding points as Green Bay became the first No. 6 seed from the National Conference to make it to the Super Bowl.
Green Bay will face Ben Roethlisberger's Steelers February 6 at Cowboys Stadium in Texas.
Pittsburgh punched their ticket to the showcase event by beating the New York Jets 24-19 in the second semi-final.
The Steelers are headed to their eighth Super Bowl appearance overall and it is their third trip in the past six years.
Like the Packers, the Steelers booked their Super Bowl berth by building a sizeable advantage early, then nearly blowing the lead in the second half.
"We knew we were going to have a chance to run the ball well," Steelers Rashard Mendenhall said during the post-game celebration. "The offensive line controlled the line of scrimmage."
Rodgers rushed for a one-yard touchdown on the game's opening drive, giving Green Bay a lead they would never surrender.
With Chicago starter Jay Cutler hobbled with a knee injury, Green Bay appeared to be cruising to victory before the Bears rallied behind third-string quarterback Caleb Hanie.
Under Cutler, the Bears never got inside the Packers' 30-yard line.
Cutler threw one pass in the second half and was replaced by backup Todd Collins, who went 0-for-4 passing, setting the stage for Hanie to enter the game and march the Bears downfield for two touchdowns to stay within reach down the stretch.
The two teams were meeting in a semi-final playoff game for the first time in the league's most historic rivalry. It was the 182nd meeting between the teams overall but this time a Super Bowl berth was on the line.
Rodgers, in his third season as the Packers' starting quarterback, easily won the battle of former first-round NFL Draft picks.
Rodgers was selected by Green Bay in the first round (24th overall) in the 2005 entry draft. Chicago's Cutler was chosen 11th overall in 2006.
"You have to give credit to their defence," Rodgers said. "I didn't play my best game. They had a good plan."
Hanie orchestrated the two lone Chicago scoring drives. The Bears were inside Green Bay territory in the final minute, but Hanie was intercepted on a fourth-down pass by Green Bay's Sam Shields to seal the outcome.
Green Bay players were surprised that Cutler didn't come back.
"You know if he doesn't come back it had to be serious, not to come back and play in this game," Charles Woodson said.
When Cutler went down it put the Bears in a hole that Hanie couldn't overcome.
"Just disappointment," Bears coach Lovie Smith said. "We got into a hole but the guys fought back."
In Pittsburgh, the Jets spotted the Steelers a 24-point lead as William Gay's defensive touchdown helped make it a lopsided opening half.
The Jets battled back behind quarterback Mark Sanchez who threw two second half touchdown passes, including one to Jerricho Cotchery that pulled New York within 24-19 with just over three minutes in the fourth quarter.
But Steelers Roethlisberger had the last laugh, completing a first-down pass to Heath Miller late in the fourth as the Jets ran out of timeouts.
Roethlisberger than connected with Antonio Brown on the run for a first down, sealing the victory for the Steelers.
Rashard Mendenhall scampered for a 121 yards and had a touchdown against New York, which had the third-best defence against the run in the league heading into the game.