What happened to the 49ers’ defense?

There wasn’t any doubt in this one. Oh, the final score was close, but in truth, the game wasn’t. 

That 49ers team, which only two weekends ago crushed the Dallas Cowboys and had the Faithful talking Super Bowl, has gone missing.

And worse, has gone losing in two consecutive games.

It was the very mediocre Minnesota Vikings that beat San Francisco, 22-17, Monday night at US Bank Stadium. It was a very unstoppable Vikings team that destroyed what we mistakenly believed was one of the best defenses in the NFL.

A Vikings team with apparently no running game.  A Vikings team that ran and passed the Niners to oblivion.  A Vikings team that came into the game with a 2-4 record and when it constructed a lead it surprised ESPN announcer Joe Buck to the point that he said in so many words, “What’s going on here?”  

A national audience, which had been following the Niners’ 5-0 start and reading about the magic of young quarterback Brock Purdy, $170 million pass rusher Nick Bosa and scoring machine Christian McCaffrey, surely wondered the same thing.

Or maybe wondered if all the praise and expectations that surrounded the Niners was just a lot of journalistic nonsense.  

Nobody expects the Niners to go unbeaten. This isn’t 1972, and now the schedule is 17 games and there’s too much talent on every franchise. So, getting beat by the Cleveland Browns, 19-17, eight days earlier was acceptable.

This one against the Vikings wasn’t if you’re thinking about the championship.

What Niners head coach Kyle Shanahan was thinking we never might know, but what he said was, “They had one turnover, we had three turnovers. It was a five-point game, so it's almost as simple as that."

A game decided perhaps by the Vikings constantly blitzing Purdy, whose passing was 21 of 30 for 272 yards. He also threw two interceptions and was sacked once. He was under pressure from the start.

The 49ers couldn’t match that pressure. They didn’t have a chance.

What the Niners did have at one point in the second half was their largest deficit of the season, 19-7. And what they never had for the first time in any game was a lead.  

The Vikings, with the often-maligned Kirk Cousins at quarterback, had a brilliant game on offense as well as defense. Minnesota gained 452 yards, San Francisco 325.

McCaffrey, who was questionable because of an oblique injury, played and got into the end zone twice, extending his team-record touchdown streak to 16 consecutive games. But he fumbled on an early drive, and perhaps that changed the momentum of the entire game. 

Purdy made some key completions as the Niners tried to catch up, but hounded he lofted a ball that was intercepted, ending any chance for a comeback. 

“It was a tough day,” said Purdy. “The Vikings played a very smart game, and we couldn’t quite do it.”

“We can’t sit here and worry about what happened,” said Shanahan. “We have got to find a way to beat the Bengals (the Niners’ next opponent). And then we go into our bye week. We’ve got to take this like men.”

What they took was a figurative punch in the gut. Now there are questions about Purdy, and even worse, questions about the supposedly impregnable San Francisco defense.

A few days ago Shanahan told the media, referring to the defeat in Cleveland, “We haven’t had that for a while. I forgot how it felt after a loss.”

There will be no forgetting now.