Down 14-0 just over four minutes into their NFC playoff game against Seattle, the Packers resisted wilting despite two costly turnovers and a recent playoff history that wasn't on their side in a 42-20 victory over the Seahawks.
The last playoff game at Lambeau Field turned out to be brutal for the Cheesehead faithful, with Green Bay falling behind 17-0 to the Minnesota Vikings in a 2004 NFC wild-card game that left Randy Moss mooning the crowd.
This one was much different.
After falling behind early, the Packers scored on their next six drives with a certain symmetry - Brett Favre threw three touchdown passes and Ryan Grant ran for three more - as Green Bay gained 408 yards of offense.
McCarthy, who took over after general manager Ted Thompson fired Mike Sherman following the 2005 season, turned a group trained to look for Favre to make big plays - and often saw him make costly interceptions - into a team that moved the ball efficiently and effectively.
Forget that the Packers didn't find their running back until Grant emerged in midseason, didn't have a tested wide receiver beyond Donald Driver, and had an unhappy Favre bemoaning Thompson's reluctance to make a trade for Moss in the offseason.
McCarthy, Favre's quarterbacks coach in 1999 after six years with the Chiefs, moved on to New Orleans as the offensive coordinator, then spent a year in San Francisco working with No. 1 draft pick Alex Smith.
Still, his resume was hardly full of experience when he took over in Green Bay.
He didn't get off to a fast start, either, sinking to 4-8 before winning four straight to end last season. But since then, McCarthy has kept winning, off to the best coaching start in Packers history through 25 games, with the team matching a franchise-record with 13 wins this season.
Now he's got his first postseason win, too, and kept his title dreams alive in his second year, something it took Vince Lombardi three seasons to accomplish.
McCarthy did it by suppressing Favre's itch to force the deep ball while working on a consistent running game that finally came around.
Thompson, meanwhile, built a deep, young and explosive defense flanked by experience at key positions with defensive end Aaron Kampman, linebacker Nick Barnett and Pro Bowl cornerbacks Al Harris and Charles Woodson.
That experience paid off against the Seahawks, who had 10 starters who also started in the Super Bowl two years ago. Seattle managed 28 yards rushing and 200 yards of offense as the receivers dropped passes at the worst moments, notably when Marcus Pollard let one slip through his hands in the end zone.
Those mistakes were more than enough for the Packers, who kept building momentum with touchdowns on every drive. They let the defense tee off with safeties Atari Bigby and Nick Collins making big hits while Harris and Woodson shut down the Seahawks' top receivers.