Elite quarterbacks torch the Green Bay secondary.
Quarterbacks Ben Roethlisberger and Brett Favre have annihilated the Packers through the air this season to the tune of 1,018 yards on 66.6 percent passing, with 10 touchdowns against zero interceptions.
Roethlisberger picked up where Favre left off Sunday, carving up the Packers' pass defense for a Steeler-record 503 yards as he repeatedly found Hines Ward, Heath Miller, and, on two critical plays, Mike Wallace to pull out a heart-stopping win 37-36 win.
So what happened to that No. 2 ranked defense and a secondary often described as one of the league's finest?
Unlike the Minnesota games, however, it's tough to pin this debacle on the pass rush of the Packers, as Green Bay sacked Roethlisberger five times and hurried him on several other attempts.
But Big Ben was able to do the things that make him a great quarterback, displaying pocket toughness and the ability to buy enough time for his receivers to get open for big plays down the field.
And they got open. A lot.
Nickel back Jarrett Bush got abused all game and the Packers lack of depth at corner was exposed by a talented group of Steeler receivers.
The linebackers also struggled in coverage, as tight end Heath Miller unsurprisingly had his way with A.J. Hawk for most of the day.
Even Charles Woodson struggled at times, picking up two key holding penalties and failing to make the big play that has been his staple all season.
Outside of Tramon Williams, the Packers have struggled to develop anyone behind their shutdown tandem of Woodson and Al Harris. And with an army of NFC playoff contenders loaded with play-makers at wide receiver, that lack of development and depth will be exposed again.
The good news for the Packers is that they haven't ran into many top signal-callers so far this season.
The defense has been able to beat up on the likes of Jay Cutler, Kyle Boller, Matthew Stafford, Derek Anderson, Alex Smith, and Joe Flacco in victory, while the only solid quarterback that the Packers have been able to control this season was Dallas' Tony Romo.
Unfortunately, the playoffs don't often feature the kind of mediocrity behind center that the Packers have been able to dominate.
Aaron Rodgers and Co. may indeed be able to out-duel a team or two in the postseason, but after Sunday's defensive performance one thing is now crystal clear.
They'll have to.