MINNEAPOLIS — On the verge of an improbable victory Sunday, the San Francisco 49ers instead endured an all-too-familiar sight:

Brett Favre. Again.
The quarterback who won’t go away stuck a 32-yard dagger into the 49ers’ hearts with two seconds remaining, turning a potential feel-good victory into a feeling-sick 27-24 defeat.
Greg Lewis caught the ball in the back of the end zone, a step ahead of safety Mark Roman, and managed to keep both feet inbounds. It marked Favre’s 42nd career fourth-quarter comeback and kept Minnesota unbeaten.
The catch required an official’s video review. But when referee Jerome Boger finally signaled touchdown, 63,398 pairs of arms at the Metrodome signaled touchdown as well.
Their hands went up.
The 49ers’ hearts sank.
In the dreary silence of the locker room, 49ers coach Mike Singletary commanded every player’s attention.
“Don’t be looking down at the floor for anybody,” he bellowed. “You didn’t steal anything. You didn’t do anything wrong. OK? We’re going to get better! We’re going to get there!
“We’ll see them again “” in the playoffs. Hold your heads up. Put your shoulders back and let’s rock.”
The loss denied the 49ers their first 3-0 start since 1998. They were within one defensive stop of getting there, despite having star running back Frank Gore for only one carry. (Gore aggravated a right-ankle injury in the first quarter).
Quarterback Shaun Hill and tight end Vernon Davis had kept the 49ers afloat with two touchdown connections. The second one came on second-and-goal from the 20, with Davis making a leaping catch between free safety Madieu Williams and linebacker E.J. Henderson.
That gave the 49ers a 24-20 lead with 8:12 to play.
In all, Davis had seven catches for a career-high 96 yards.
“At the end of the day,” he said, “I don’t think it means anything”
Favre, playing in his first home game for his new team, made Davis’ highlights irrelevant when the 49ers gave the quarterback one final chance. The 49ers tried running out the clock with three running plays on their last possession but were forced to punt with 1:36 to play.
Singletary was asked if the 49ers considered a pass on their last sequence, since a first down would have sealed the victory.
“What we did, I totally support,” he said. “I don’t go back and try to analyze why.”
The Vikings’ drive started at their 20 with 1:29 remaining. Favre, famous for his big armed, nickel-and-dimed his way down the field “” then cashed in on the final play.
On third-and-three from the 49ers’ 32, with 12 seconds on the clock, the Vikings had one last shot. Minnesota defensive end Jared Allen thought to himself, “Be Brett. One time. Just be Brett.”
Favre escaped pressure from defensive end Justin Smith and stepped up in the pocket just as linebacker Manny Lawson was closing in. Lawson came close to a game-winning sack. “Not close enough,” he said.
Instead, Favre unleashed a laser of a throw to Lewis, a 29-year-old who was signed Sept. 10 after the Patriots cut him. Favre later said he had no idea to whom he was throwing when he let the ball go.
Lewis had been on the field for all of four snaps. He was supposed to be on the left side, but he improvised as Favre bought time.
“I was like, ’Well, I can’t get the ball this far over, so let me go see what’s going to happen over here,’ “ Lewis said.
What happened is that Lewis got a step on Roman — who was playing in his 100th consecutive game — along the back line. None of the other defenders was close enough to make a play.
“That’s just Brett,” 49ers linebacker Takeo Spikes said.
The 49ers ought to know. Favre is 12-2 against them in his career, including the playoffs. Overall, Favre finished with 301 passing yards “” his 56th career 300-yard game and the first by a Viking since Daunte Culpepper in 2005.
Entering play, Favre had totaled just 265 total over the Vikings’ first two victories.
“I’m worn out. Believe me, I could fall right now,” said Favre, who turns 40 on Oct. 10. “I don’t know how many plays we had, but it felt like two years’ worth of plays.
“I’m telling you: They are a fine football team. Their defense is aggressive.”
Until that final play, the 49ers looked as if they were going to take an unlikely path to a monumental victory.
They led despite going 0-for-11 on third-down conversions and despite playing with rookie Glen Coffee in Gore’s place at running back.
The 49ers stuck around thanks in part to a big play before halftime, when Ray McDonald blocked a field-goal attempt and Nate Clements ran it back 59 yards for a touchdown. The momentum swing gave the 49ers a 14-13 lead at halftime.
Minnesota countered that big play with rookie Percy Harvin’s 101-yard kickoff return in the third quarter, which gave the Vikings a 20-17 lead.
The play took a lot out of Harvin, which is why he ran out of gas in the final seconds. That’s why Lewis came on the field to replace him for the improvised touchdown catch.
“We haven’t practiced that play, I assure you,” Favre said.
The 49ers’ though, might have felt as if they had seen it before.