Chicago will play the resurgent New Orleans Saints next Sunday for the right to advance to the Superbowl in Miami on February 4.
The Saints edged out the Philadelphia Eagles by an identical 27-24 on Saturday.
New England Patriots shocked the San Diego Chargers on Sunday, winning 24-21 to move within one win of their fourth Super Bowl trip in six seasons.
Tom Brady overcame three interceptions, his career playoff high, to lead the Patriots to 11 points in 3:26 late in the game.
With the Patriots trailing 21-13 at San Diego's Qualcomm stadium, Brady threw a 4-yard touchdown pass to the wide-open Caldwell with 4:36 to play.
The Patriots tied it on a tricky 2-point conversion, snapping the ball directly to running back Kevin Faulk, who was standing next to Brady and ran through the middle of the line.
The winning points came on a 31-yard field goal by Stephen Gostkowski with 1:10 left.
That capped a 72-yard drive highlighted by a 49-yard pass to Reche Caldwell, who left the Chargers as a free agent after last season.
San Diego's Pro Bowl kicker Nate Kaeding was short on a 54-yard field goal try with three seconds left.
It was a crunching end to San Diego's season, and could lead to coach Marty Schottenheimer's departure.