Kirk Cousins spent his first three quarters as a Viking mimicking the passing skills of Fran Tarkenton. Late in the fourth quarter, with the lead leaking air, the offense in neutral and fake grass beckoning, Cousins decided to pay homage to the pugilistic tendencies of Joe Kapp.

On third-and-5 from the Vikings 37 and less than three minutes remaining, Cousins bolted up the middle as two 49ers performed a pincer movement. Instead of sliding, Cousins lowered his head and right shoulder — both of which could come in handy in the near future — and tried to ram his way to a first down.

He took a blow to his shoulder, landed on his head, fell short and made 52 new best friends. Cousins’ precision passing built the lead that led to the Vikings’ 24-16 victory over San Francisco at U.S. Bank Stadium on Sunday. His reckless disregard for safety led to head shakes and fist bumps in the postgame locker room.

‘‘I thought, ‘That’s our quarterback,’ “ running back Latavius Murray said. ‘‘That’s what makes him who he is. For a quarterback to lower his shoulder and give his body up, that’s motivating, that’s inspiring, because you don’t see a lot of quarterbacks doing that.”

Let’s be clear: The decision was also crazy. Cousins was playing in the first game of a promising season after signing a three-year contract worth $84 million guaranteed. His decision was irrational, and that’s what his teammates liked — Cousins put team above health, and football players, bless their jangled brains, respect nothing more.

‘‘I loved it,” Harrison Smith said. ‘‘I don’t know if our front office and coaches loved it, but I loved it.”

‘‘I was like, ‘What is he doing?’ “ Everson Griffen said. ‘‘If you want it, go get it. I respect it.”

‘‘I’ve talked about it all offseason, how big a competitor he is,” Kyle Rudolph said. ‘‘A lot of guys wouldn’t have done that. Kirk is the biggest competitor I’ve ever been around. In practice every day, every single play, he hates losing.”

Last weekend, Rudolph and Cousins played charades at Adam Thielen’s house.

‘‘He hated to lose then, too,” Rudolph said. ‘‘It kills him.”

Cousins completed 20 of 36 passes for 244 yards, two touchdowns and no interceptions despite dealing with constant pressure. He threw a few questionable passes, and was kicking himself for a long attempt to Thielen that hit the back of a defender, but he demonstrated his worth on the two touchdown passes, which were threaded into spaces the size of a French bulldog.

‘‘I think that’s NFL football,” Cousins said. ‘‘I think if you’re not really accurate and you don’t have that confidence to let it rip you’re going to be holding the ball and getting sacked, you’re going to be spraying it everywhere. If you’re waiting for guys to get open you’re going to be waiting a long time.”

As Cousins stepped off the podium following his postgame news conference, a youngster approached and said he was from Lakeville. Cousins said, ‘‘I saw that Lakeville North beat Eden Prairie.” Then Cousins asked if he could sign an autograph.

Cousins could sell black ice to Minnesotans. Proving yourself to 52 teammates risking their neurons can be tougher.

‘‘Yeah, you know we always talk about sliding and protecting yourself, but in that situation, right at the chains, I think you’ve got to do something,” Cousins said. ‘‘Maybe the right move wasn’t to dive, but to try to make him miss, do something. You want to take a hit because at that point if you get the first down you change the whole game.”

His charades partner wishes he’d imitate a baseball player sliding into second.

‘‘I wish he wouldn’t do that,” Thielen said. ‘‘But he’s a winner. I said, ‘What are you doing? Just relax, we need you the whole season.’ ”

Cousins decided to risk just about everything, for a yard. That kind of calculus can cost you consciousness, or win over an entire franchise.

Jim Souhan’s podcasts can be found at TalkNorth.com. On Twitter: @SouhanStrib. jsouhan@startribune.com