“We ran [that play] once [earlier in the game] and it wasn’t as big as we thought it would be,” said Lacy, who finished with 141 yards and eclipsed the 1,000-yard mark for the season. “But we came back to it and it was a big hole. Everybody made their blocks and it created a big hole for me.”

It was the first of many plays the Packers would make in the second half. After the Cowboys answered with a field goal, Flynn led the Packers on another 80-yard drive, picking up a crucial third-and-8 with a 22-yard completion to tight end Andrew Quarless, then hitting Nelson for 21 yards to convert a third-and-10. When Flynn hooked up with Quarless on a 3-yard touchdown to make it 29-17, the comeback was officially on.

The Packers defense followed with a three-and-out stop – one that included a 13-yard sack of Tony Romo by Clay Matthews and Datone Jones – and Micah Hyde’s 26-yard punt return put the Packers back in business at the Dallas 22. Five plays later, James Starks’ 11-yard touchdown on a middle screen made it 29-24 with 12:47 to play.

Then came Williams’ interception that wasn’t, as referee Walt Coleman overturned the call upon further review. Instead of having the ball at the Dallas 8 with a chance to take the lead, the Packers watched the Cowboys go right down the field en route to Dez Bryant’s 5-yard TD catch. At 36-24 with 7:55 to go, the Packers looked finished.

But just like they had the week before, rallying from a 21-10 halftime deficit to beat Atlanta, they answered. Flynn engineered the Packers’ fourth 80-yard touchdown drive of the game, with Quarless (a 14-yard catch on third-and-6) and Jarrett Boykin (a 27-yard back-shoulder catch to the Dallas 7) setting up Jones’ 3-yard TD catch with 4:17 to play.

Just believe, man. Just believe.

“I was on the sideline talking to Sam (Shields) and Morgan (Burnett) and I was like, ‘We just need to score before the 4-minute mark.’ And we did,” Williams said of his thoughts after the overturned INT and ensuing touchdown. “I was like, ‘OK, we’re good. We’re in this.’ We just needed to make a stop at that point. And we did.”

Did they ever. After converting a third-and-12 with a 13-yard completion to Bryant, Romo faced second-and-6 from the Dallas 35 with 2:58 to play. Inexplicably, he audibled out of a run call and instead threw across the middle to Miles Austin, who had a step on Shields on a slant. But somehow, Shields recovered, snatched the interception and gave Green Bay the ball at midfield.

Asked if he was surprised the Cowboys threw the ball at that point, Shields replied, “I was, but he was open. As you could see. He was open. I just used my speed to get back up and get the ball.”

After the game, Cowboys coach Jason Garrett told reporters of Romo’s decision and said of his quarterback, “He’ll be the first one to tell you now that we probably should have run the ball in that situation.”

Said Romo: “They overloaded the side we were going to run the ball to. I ended up throwing to the man that was 1-on-1. It was my fault for obviously putting the ball in a position where the defense could make a play.”

Romo would do that again later, too – but not before the Packers took the lead. Quarless’ 18-yard catch started the drive, and Lacy had runs of 4-, 7 and 9 yards before bulling for a 3-yard gain on third-and-1 from the Dallas 4. On the next play, Lacy crashed in from a yard out for the 37-36 lead with 1:31 to play, with defensive linemen Mike Daniels and Raji in as extra blockers. It was the first time the Packers had led all day.

“We kind of were talking on the sideline [before that], ‘Let’s just get this thing to the wire. Let’s get this thing to the fourth quarter and the last couple minutes,’” Flynn said. “Kind of like I said last week, this one feels so great because it was such a team victory. It wasn’t one-sided. It was offense and defense both stepping up in that second half and really feeding off each other.”

The defense still had to come through one more time, knowing a field goal could still win the game for Dallas. But when Romo and wide receiver Cole Beasley got their signals crossed on a quick out route and the ball was flung too wide to the sideline, Williams came off Austin and plucked the ball inches off the ground. Although side judge Rick Patterson vehemently signaled incomplete, Williams knew better.

“I never felt more sure about a catch in my life,” he said.

And he was right.

Just believe, man. Just believe.

“Just to see the emotion of guys, what we overcame, I don’t have the words. My vocabulary’s stuck right now,” McCarthy said. “I need some water, frankly. It was incredible. It took me everything not to cry.”

Listen to Jason Wilde every weekday from 9 a.m. to 10 a.m. on “Green & Gold Today” on 540 ESPN, and follow him on Twitter at twitter.com/jasonjwilde.