They did so by limiting the high-powered Green Bay offense to just 315 total yards and only 14 points.
Here are eight things that we learned from this huge Chiefs' victory in Week 15 against the Packers.
Heading into this game, it appeared Chiefs' interim coach Romeo Crennel had a lot on his plate.
His team was coming off of a blowout loss in their last game, he was starting a new QB and on top of all that: The Chiefs were facing the best offense in the league.
When the dust settled on Sunday afternoon, Romeo had the look of a hero after his team was able to pull of an improbable win in his first game at the helm.
If anything, this win could really help get Crennel's foot in the door to becoming the next permanent head coach of the Kansas City Chiefs.
Some thought that new signal-caller Kyle Orton might have his struggles with a different offensive system and new personnel when he took the field for the Chiefs on Sunday.
However, none of that was the case in this game.
The former Broncos QB had a great day, completing 23 of 31 passes for 299 yards, while looking very comfortable in the pocket for most of the afternoon.
If he continues to play like this over the next two weeks, the Chiefs brass will have a tough decision when it comes to re-signing him this offseason.
Why do the Chiefs need TE Tony Moeaki when they already have Leonard Pope?
Alright, in all seriousness, Pope will likely not be the long-term TE for the future of this franchise. But in Sunday's game against the Packers, that's exactly what he looked like.
He had two big catches for 72 yards, and at 6'9" 264 lbs he was a clear mismatch for the Green Bay defense all game long.
We've all seen this happen before.
First, the Chiefs struggled to score TDs with Matt Cassel.
Then, it was journeyman QB Tyler Palko who couldn't get the KC offense into the end zone.
Now, it's new starting quarterback Kyle Orton—who was only able to score one measly touchdown with Kansas City's offense in a game where the Chiefs were still able to win on the strength of four field goals from kicker Ryan Succop.
Chiefs kicker Ryan Succop has been money so far this season.
He has now made 22 of his 25 field goal attempts for the season, which comes out to 88 percent for the year.
He's also made 21 straight kicks—the best streak out of all active kickers in the league.
The former South Carolina Gamecock has never made a Pro Bowl, but that could all change this season after the type of numbers that he has been putting up for the Chiefs.
You can't say enough about how impressive the Chiefs' defense was against the vaunted Packers offensive attack on Sunday.
They held Pro Bowl RB Aaron Rodgers to just 235 yards passing while sacking him four times in the contest.
Interim head coach Romeo Crennel really had a great defensive plan in this game, and his team did a really nice job of executing it to perfection against the Pack.
After shutting down both the Steelers and the Packers this season, this KC defensive unit has now proved that they can stop any offense when they are firing on all cylinders.
Dwayne Bowe is easily the best wide receiver that the Chiefs have on their current roster. He can stretch the field in the passing game, and he is also an asset as a blocker.
Sure, he didn't have a big game on Sunday—with only four catches for 49 yards—but he is now just 14 yards away from his second straight 1,000-yard season with this team.
It's time to lock up Bowe for the long-term and keep one of the best wideouts in the league in Kansas City for many years to come.
One thing that I have learned since becoming a Chiefs fan at an early age was that you should never doubt this team when they are playing at home.
The Packers came into this game with an undefeated record this season, and were sent home with their first loss of 2011.
The Chiefs came to play in Week 15, and Green Bay was already looking ahead to the playoffs—where they will enjoy a first-round bye.
This game should be a lesson to every other NFL team: If you come into Arrowhead and underestimate KC, then they will make you pay in the end.