The Packers' previously No. 2-rated defense surrendered 537 yards -- nearly double the stingy season average of 272 yards they had allowed coming into the game.
Pittsburgh quarterback Ben Roethlisberger completed an historic performance with a 19-yard touchdown pass to rookie Mike Wallace as time expired, putting an end to both the Steelers' five-game losing streak and the Packers' five-game winning streak.
"To let one get away the last play of the game, it's a hard one to swallow," Packers head coach Mike McCarthy said.
The crushing defeat not only enabled the Minnesota Vikings to repeat as NFC North champions, but Green Bay's quest to garner an NFC wild-card playoff berth was put on hold at least another week.
With two games left to play, a burning question is whether the 9-5 Packers have a defense capable of challenging explosive offenses that they're likely to encounter in the postseason.
On the strength of 10 pass plays of 20 yards or more, Roethlisberger threw for 503 yards, the most passing yards ever allowed by Green Bay.
The previous record for an opposing quarterback was 464 yards by the Philadelphia Eagles' Donovan McNabb in 2004.
"I did not think we thought it would go that way, as far as (the Steelers') aggressiveness in the passing game against our defense," McCarthy said.
The Packers were third in the league against the pass, yielding an average of only 187 yards.
No quarterback had thrown for 225 yards in Green Bay's three previous games. Until Sunday, Green Bay allowed only three passing performances of 250-plus yards and none of 300-plus yards. The loss of veteran cornerback Al Harris to a season-ending knee injury Nov. 22 could prove to be tough to overcome. Deficiencies in pass coverage have been exposed away from Charles Woodson, a defensive player of the year candidate.
Roethlisberger's game-winner to Wallace, who started the scoring with a 60-yard touchdown grab, came against untested cornerback Josh Bell.
"When you're up like that at the end of the game and you have an opportunity to make a play to get off the field and secure the win, you have to
do it," Woodson said. "We didn't get it done."
TRENDING: The team's patience with third-year kicker Mason Crosby has all but evaporated. The Steelers' last-second dramatics Sunday would have been for naught had Crosby not missed a 34-yard field goal in the second quarter. "He needs to make the kick," head coach Mike McCarthy said. Crosby has a miss from inside 45 yards in four straight games, and all have been wide right. Regarded for his strong leg, the sixth-round draft pick from Colorado has connected on only 24 of 33 field-goal attempts this season, including a miserable 5 of 12 from 40-plus yards. Not even a switch in holders -- backup quarterback Matt Flynn gave way to punter Jeremy Kapinos on Sunday -- could keep Crosby from setting a personal high for misses, topping the eight he had as a rookie in 2007.
BY THE NUMBERS: 16 -- Wins by the Packers in their last 17 regular-season home finales. Their only loss in that span, dating to 1992, was 28-25 to the Jacksonville Jaguars in 2004.
--NT Ryan Pickett was activated for Sunday's 37-36 loss at the Pittsburgh Steelers, but the starter was primarily relegated to the sideline. Pickett had missed the previous game because of a hamstring injury and returned to practice on a limited basis last week. As such, rookie B.J. Raji had an extensive role for the second straight game.
--LB Nick Barnett aggravated a right knee injury early in the second half Sunday, but he returned to finish the game. It was the same knee in which Barnett suffered a torn ACL late in the 2008 season. Barnett expects to be fine for the week ahead.
--WR Greg Jennings hobbled off the field with an ankle injury in the third quarter, but he was out only a short time and played the rest of the game. He had a career-high 83-yard touchdown catch in the first quarter, eclipsing his 82-yard game-winner in overtime at the Denver Broncos in 2007.
--QB Aaron Rodgers also established a personal best with the 83-yard scoring strike to Jennings. Rodgers' previous career-long pass was 74 yards for a touchdown to James Jones in the Nov. 8 loss at the Tampa Bay Buccaneers. Rodgers, who was 26 of 48 for 383 yards Sunday, had a career-high-tying three touchdown passes for the fifth time this season, and he also had a 14-yard TD run.
--TE Jermichael Finley had a career-high nine catches for 74 yards, including an 11-yard touchdown early in the fourth quarter that started the Packers' comeback from a 24-14 deficit. Since returning from a knee injury that cost him three games, Finley leads the Packers with 31 receptions for 302 yards and three touchdowns in their last five games.