The rivalry between Chicago and Green Bay is the oldest and most-played rivalry in the NFL, with this the 213th meeting between the divisional rivals - and just the third in the play-offs, the others coming in 1941 and 2011.
The Bears surpassed expectations this season to win the NFC North division in Ben Johnson's first year as head coach and claim the NFC's second seed.
Green Bay claimed the seventh so had to visit a snowy Chicago for the first play-off game at Soldier Field since 2019, and during the first half it seemed the occasion may be too much for the Bears.
Packers quarterback Jordan Love returned after two games out following a concussion and threw three touchdown passes as the visitors charged into a 21-3 lead by half-time.
But Chicago's defence stepped up in the second half to stifle the Packers and a field goal made it 21-6 heading into the final quarter.
The Bears added another before second-year quarterback Caleb Williams, making his play-off debut, showed why he has been nicknamed 'the Iceman' by leading his team to touchdowns on three straight possessions.
D'Andre Swift got in from close range before Love made his fourth touchdown pass to halt Chicago's momentum, again making it a two-score game at 27-16.
Yet Williams, the first overall draft pick in 2024, was undeterred, finding Olamide Zaccheaus and DJ Moore either side of a second missed field goal by Green Bay kicker Brandon McManus, to put the hosts in front with 1:43 remaining.
Chicago actually lost the turnover battle, with Williams throwing two interceptions along with two touchdown passes, but it was the 24-year-old's composure when their season was on the line that allowed the long-suffering Bears fans to celebrate a famous victory.