And once the Bears got to the extra period, reliable Robbie Gould kicked a 38-yard field goal for a 20-17 win.
Now, after the icy victory, the Bears are still in the running for the playoffs.
"We got a great push from a lot of different people. I was just the one who got my hand on it," Brown said.
"We were saying on the sidelines that we have to block it. I got through pretty good but I didn't really think that was going to happen. You just go as hard as you can and see if you can get a hand up and hopefully you can get it."
The Bears (9-6), who stayed in contention for the NFC North over the weekend when Atlanta beat Minnesota, won their third straight and rallied from a 14-3 halftime deficit to do it.
If the Bears win at Houston next Sunday and the Vikings lose at home to the Giants, Chicago captures the NFC North. Minnesota holds the tiebreaker over the Bears, so if both teams win on the final Sunday, the Vikings win the division. But Chicago is still alive for a wild-card berth, too.
"Everything fell right, gave us a lot of momentum and energy coming into this game. We just had to carry it all the way through," quarterback Kyle Orton said.
And the Bears had to overcome the elements, too, as did the Packers.
The temperature at Soldier Field was announced at 2 degrees, making it the coldest home game in Bears' history since records started being kept in 1963. The wind chill was 13 below, the second-lowest in recorded team annals, so the longtime rivals known for their ability to play in cold weather were tested by the elements.
Orton hit a 17-yard pass to Greg Olsen and a 15-yard penalty on Green Bay's Aaron Rouse for a horse collar tackle gave the Bears the ball at the Green Bay 35 in overtime. A third-down pass of 14 yards to Matt Forte got it to the Green Bay 20 to set up the winning kick -- Gould's second straight game-winner in overtime.
"You know it's going to be chilly, the ground is going to be hard. You've just got to go out there and do your job. There's no excuses for missing," Gould said
Green Bay (5-10) dominated the first half, but lost its fifth straight after routing the Bears 37-3 at Lambeau Field in mid-November.
"It's disappointing. It's tough. It's frustrating," Green Bay quarterback Aaron Rodgers said.
Forte's 3-yard TD with 3:11 left lifted the Bears into a tie. The score came one play after Forte just made a first down on a fourth-and-2 run.
Rodgers' third down pass of 9 yards to James Jones gave the Packers a first down at the Bears 24 with two minutes left.
The Packers ran down the clock behind the running of Ryan Grant, moving to the 20 and trying to set up a game-winner from Crosby, but Brown blocked the kick.
"I have been hitting the ball well this year and I have been making kicks and it just didn't fall our way this game," Crosby said. "Everything has to be right and I just didn't finish my end of the deal."
In the first half, Rodgers had plenty of time to throw and completed 16 of 24 passes for 176 yards, throwing TD passes to Greg Jennings and Grant as Green Bay moved ahead 14-3.
He finished 24-of-39 for 260 yards.
The Bears, meanwhile, sputtered and were outgained 221-48 in the first two quarters as their playoff hopes were on the verge of evaporating into the cold air.
"There was a lot of talk going on in the offensive huddle 'we've got to do it now.' We weren't playing good," Orton said. "We weren't running the ball. We weren't throwing the ball. We just weren't playing well at all. We just said, 'This is our season. It's coming down to this. And if we don't do anything, we're done.'"
Charles Woodson's sixth interception of the season and a return to the 30 helped the Packers move to the 5, but the Bears held and forced a 28-yard field goal from Crosby that put Green Bay up 17-10 early in the final quarter.
Forte, who had only 20 yards rushing through the first three quarters, broke off a 28-yard run to the Packers 23 late in the final quarter. Forte had two more carries to give Chicago a first down at the 12. Two more runs by Forte and a pass to Devin Hester left the Bears with a fourth-and-2 from the Packers 4 with just under four minutes left. Forte just got the first down and the Bears were able to tie it.
Chicago got a break on its first possession of the third quarter when Brad Maynard's punt hit Green Bay's Jarrett Bush, who was blocking on the play, and the Bears' Jason Davis recovered at the 27. Three plays after a 21-yard pass to Desmond Clark, Orton hit Olsen on a 3-yard TD pass, making it 14-10.
Using some trickery, the Packers moved in for a 7-0 lead with 6:21 left in the second quarter.
The Packers faked a punt on a fourth-and-2 from the Bears 37, snapping the ball to backup quarterback Matt Flynn, who carried 6 yards for the first down.
From there Grant carried four straight times for 24 yards to the 7. And on a third down, Rogers found Jennings with the TD pass that capped the 14-play, 91-yard drive.
It was the 177th meeting between the teams, including one in the playoffs. The Bears lead the series 91-80-6. ... Bears S Mike Brown injured his calf late in the second quarter and did not return.