Rookie defensive end Datone Jones scooped up the fumble and returned it 20 yards to the Ravens' 13-yard line to set up Mason Crosby's 31-yard field goal on the final play of the first half.
It was exactly the kind of play that, according to Packers linebacker A.J. Hawk, great defenses make.
"We're definitely not a great defense yet," Hawk said after the Packers' 19-17 victory over the defending Super Bowl champs. "But we're trying to get there."
The Packers defense might have to get there -- and fast.
If the Packers (3-2) are going to be without receivers Randall Cobb and James Jones, both of whom left Sunday's game with injuries in the first half, then they're going to need their defense to pick up where it left off on Sunday at M&T Bank Stadium.
Among its noteworthy accomplishments in helping secure Green Bay's first road win of the season, the defense came through with:
A stop on fourth-and-goal from the 1-yard line in the second quarter after a special teams gaffe by John Kuhn, who touched a blocked punt that the Ravens recovered to keep a drive alive.
A stop on third-and-goal from the 5 in the third quarter that forced the Ravens to settle for a field goal.
Five sacks, including three by Hawk (who had that many all of last season).
A near complete shutdown of the Ravens' once-prolific running game.
"Today was good, I think, with those goal-line stands," Hawk said. "But you can't call yourself great until you're holding teams consistently under 13, 14 points, I think. We played pretty well, but it's a long season, that's for sure. We're only 3-2."
Perhaps most encouraging for the Packers was that they did it all without their best defensive player, outside linebacker Clay Matthews, who six days earlier underwent surgery to repair his broken right thumb, and without their defensive signal-caller, inside linebacker Brad Jones, who sustained a hamstring injury a week earlier against the Detroit Lions.
It all began with the goal-line stand.
On fourth-down from the Packers' 1-yard line, the Ravens called running back Bernard Pierce's number. Defensive tackle Mike Daniels and cornerback Micah Hyde were credited for stopping Pierce, but in reality it was a group effort that included Hawk and defensive tackles B.J. Raji and Mike Daniels.
"We pride ourselves on not giving up any rushing touchdowns," Raji said. "We stood up that play, and hopefully we can continue to do that."
Aaron Rodgers threw for 315 yards, but he also lost two receivers to injuries.
Just as important was the stop on third-and-goal from the 5 in the third quarter, when the Packers forced an incompletion by Flacco to receiver Marlon Brown. Linebacker Jamari Lattimore, the replacement for Jones, had tight coverage on the play. The Ravens settled for a field goal, cutting the Packers' lead to 9-3 with 4:34 left in the third quarter, and then on the next possession quarterback Aaron Rodgers finally hit on a big play -- a deep shot to receiver Jordy Nelson for a 64-yard touchdown.
"Like I tell Dom after a game like this on Monday, if you give up 17 points, we're going to win most of those games," said Rodgers, who was pressured often but still managed to throw for 315 yards on 17-of-32 passing with one touchdown and one interception.
To be sure, the Packers weren't facing an offensive juggernaut. The Ravens came into the game ranked 21st in total offense, and they haven't been able to protect Flacco. Even their usually reliable ground game with running back Ray Rice was just 27th in the league in yards per game coming in.
The Packers shut down Rice, who rushed 14 times for 34 yards, 11 of which came on one carry. They will almost certainly climb from their No. 5 ranking last week in rushing defense.
"The defense, I felt, carried us pretty much most of the game," Packers coach Mike McCarthy said.
That's not to say the Packers were perfect on that side of the ball. They had a major breakdown when the Ravens went for it on fourth-and-21 from their own 19-yard line with 2:40 left in the game. Safety Jerron McMillian fell down in coverage, which allowed Flacco to hit receiver Tandon Doss for a 63-yard completion. That set up an 18-yard touchdown pass to tight end Dallas Clark over McMillian on the next play, when McMillian said he did not hear the defensive call.
With the Ravens within two, the Packers needed their offense to burn off the final 2 minutes, 4 seconds. The combination of Eddie Lacy (who rushed for a career-high 120 yards on 23 carries) and a key third-down conversion to tight end Jermichael Finley (who should have stayed in bounds to keep the clock running after his 52-yard catch and run) did just that.
But with Cobb on crutches after the game and Jones having trouble walking, the fate of the Packers might rest on the defense.
"We're going to need them big," Finley said of the defense. "But at the same time, if Randall and James are out, it's called the next man up."