On his last play in his first home game as a Viking, a rival franchise's exiled legend threw a last second, game-winning touchdown pass he didn't see on a play he didn't remember practicing to a receiver he had barely met.

This is what it means to be Brett Favre.

This is what it means to have Brett Favre.

This is what it means to watch Brett Favre.

"I was on the sidelines saying, 'Be Brett, be Brett, be Brett,' " defensive end Jared Allen said. "The Silver Fox came through."

As a prelude to his grudge match with the Packers and an homage to what he did to the Vikings as a Packer, Favre displayed the agony and the ecstacy of Favre-watching in one long afternoon.

He threw lasers to receivers who didn't know they were open. He threw shotgunned mallards toward grateful defenders. He sprinted downfield to body-block one of the best linebackers alive.

He limped and winced, looking older than pyramid dust, and, just when you started wondering why he ever left the Mississippi ranch with the ornate F on the gate, Favre led the kind of drive the Vikings envisioned when they let him treat them like lovestruck teenagers all summer.

The 49ers had taken a 24-20 lead early in the fourth. The Vikings went three-and-out, then failed on a fourth-and-5 on their next two drives.

On their final drive, they took over on their 20 with 1:29 and no timeouts remaining. "I was thinking, 'It's a little too late,'" Favre said. "That's not to say you don't go out and sling it."

The Vikings' offense hadn't scored a touchdown since midway through the first quarter, as the 49ers' physical defense contained Adrian Peterson and battered Favre.

Favre feigned optimism.

"He came into the huddle and said, 'We're going to get this done,'" receiver Greg Lewis said.

Favre hit Visanthe Shiancoe for 12, then Sidney Rice for 9. After an incompletion, a short pass to Percy Harvin gave the Vikings a first down at their 41. Favre spiked the ball with 40 seconds left.

On the next play, he rolled left and tried to throw deep down the right sideline for Rice, who caught the ball out of bounds. Then Favre threw to Harvin for 15 yards and spiked it with 16 seconds left.

Instead of lobbing a pass to the end zone, Favre threw short to Bernard Berrian, who stepped out of bounds at the 49ers 32 with 12 seconds remaining.

"I wanted to be able to drill one," Favre said. "It's still hard to make it work, but I thought that was better than laying one up."

He took the next snap, faked left, and rolled right. He dodged one pass-rusher, stepped up in the pocket and unleashed a four-seam fastball toward the back of the end zone just as linebacker Manny Lawson hit him in the back, driving him face-first into the turf.

"I saw the ball flying," center John Sullivan said. "I didn't see who was going to catch it, though."

Favre had spotted a flash of purple in the back of the end zone.

"I didn't know who it was," he said.

It was Lewis, the only player newer to the Vikings roster than Favre, and like him another veteran signed in part because of his relationship with coach Brad Childress.

Lewis had taken three snaps in the game before the final play. Favre had thrown only "a couple of hitch patterns" to Lewis in their practice time together. Lewis described the play he was running as something Favre "drew up in the dirt."

Favre's four-seam fastball hit Lewis in stride, Lewis dragged his feet in bounds, and Favre, still on his belly, heard a familiar roar.

"I was in disbelief," Allen said. "The way the place erupted, that gives you chills. That brings you back to Pop Warner days, to the way you felt back then.

"That man has a little mojo on his side."

A lineman yanked Favre to his feet to celebrate; Favre probably needed the lift. He has taken nine sacks and many more hard hits during his first three games in purple, and when reporters entered the locker room Sunday afternoon he sat alone at his corner stall, still wearing his uniform pants and ankle tape.

His face still red, Favre slowly rubbed his right hand over the cropped grey on his head and chin, looking more like a mourner than the guy who just raised 120,000 hands in the air.

For the 42nd time, Favre had led a fourth-quarter comeback victory. For the first time, Vikings fans didn't need mouthguards to protect their molars when Favre started pumping his fists.

"You can't score," Favre said, "if you don't throw it down there."

Favre leaned heavily on the podium as he talked, saying he was so tired he might just fall down.

"I am wore out," he said.

Imagine if he'd had to watch.

Jim Souhan can be heard at 10-noon Sunday, and 6:40 a.m. Monday, Tuesday, Thursday and Friday on AM-1500. His twitter name is SouhanStrib. jsouhan@startribune.com