The Vikings seethed Sunday as their second-year quarterback, Teddy Bridgewater, lay facedown on the turf at TCF Bank Stadium, eyes closed and seemingly knocked out cold from the shoulder of hard-charging St. Louis Rams rookie cornerback Lamarcus Joyner.

Their afternoon matchup with the Rams had been an especially violent affair featuring two playoff hopefuls with top-10 defenses and tackle-breaking running backs. But if the chippy Rams hadn't crossed the line already, the Vikings felt they barreled over it with Joyner's fourth-quarter personal foul, the one that concussed and sidelined their quarterback.

Instead of seeking vengeance by similarly headhunting one of the Rams' playmakers, they resolved to hurt the visitors on the scoreboard. Keeping their collective cool, the Vikings made enough plays without Bridgewater to beat St. Louis 21-18 in overtime for their fourth consecutive victory and a tie for the NFC North lead.

"We knew they were going to come out and try to get under our skin. But I think we did well of holding on our composure and fighting back," cornerback Captain Munnerlyn said, adding, "We lost our quarterback, but this team didn't get down."

The Vikings led 18-15 early in the fourth quarter when Bridgewater was flushed out of the pocket. After picking up a first down, he slid down to give himself up. But Joyner followed through on his hit anyway, leveling the quarterback with his left shoulder.

Joyner claimed it wasn't his intent to injure Bridgewater and that he pulled up to avoid hitting the defenseless quarterback. But the Vikings weren't buying it, especially not after Bridgewater limped off in the third quarter after a low and late hit by Rams defensive end William Hayes.

"I don't agree with the hit," left guard Brandon Fusco said. "I think some of those players on that team are pretty cheap, to tell you the truth. I hope we see them again."

Coach Mike Zimmer, who agreed the hit was "cheap," didn't mince words after the win.

"If we were out in the street, we probably would have had a fight," Zimmer said.

Shaun Hill, who started eight games for the Rams last season, stepped in for Bridgewater. With Hill completing just two of his six throws for 15 yards, the Vikings could not sustain drives on their final four possessions in regulation.

That put the pressure on Zimmer's defense, which did a respectable job against Rams star rookie running back Todd Gurley but had trouble containing do-it-all jitterbug Tavon Austin during the first three quarters of the gamey.

They dodged one bullet when St. Louis kicker Greg Zuerlein, who drilled a 61-yard field goal in the second quarter, missed a 48-yard field goal with 1 minute, 42 seconds left in regulation. But the Rams got the ball back 28 seconds later and again put Zuerlein in position to tie the score. This time, his try from 53 yards split the uprights.

The Vikings won the coin toss before the start of overtime, but Zimmer opted to kick the ball away and instead take the wind, which whipped toward the east end zone, at his players' backs.

"It wasn't an easy [decision], I'll tell you that," Zimmer said. "The guy kicked a [61-yard] field goal earlier with the wind. I thought, 'Man, I don't want to give them an opportunity to kick another long field goal to win the game.'"

The gamble paid off. After tracking down Gurley for a 6-yard loss on first down, the defense forced a three-and-out. Then punt returner Marcus Sherels gave the offense starting position near midfield with a 26-yard runback.

Some hard running by running back Adrian Peterson, who finished the game with 125 yards on 29 carries, moved the Vikings into field-goal range. And kicker Blair Walsh connected from 40 yards for his second walk-off winner in as many weeks.

"I thought it was a hard-fought game," Zimmer said of the victory. "I know we played very clean on our side of the ball. It shows our team has a lot of heart, a lot of fight."

The win improved the Vikings to 6-2 and, coupled with Green Bay's loss to Carolina, moved them into a first-place tie with the Packers.

"There is so much football left," linebacker Chad Greenway said. "Nothing is won after eight games. They don't hand out midseason awards with congratulations."

The Vikings will travel to Oakland to play the 4-4 Raiders next Sunday. The next several days will determine if Bridgewater, who completed 13 of his 21 attempts for 144 yards and rushed for a touchdown before he was knocked out of the game, will be able to join them on the field. He must first advance through the NFL's concussion protocol.

His teammates hope to have him back under center in Oakland. But if they don't, they plan to pull together and win another game for him, just like they did Sunday.

"That's your quarterback. Everybody knows you feel something different for your quarterback than you do for anyone else," rookie wide receiver Stefon Diggs said. "He's the general and when he goes down, everybody feels like we have to step it up another notch. Our guy isn't here and we have to play for him."

Matt Vensel matt.vensel@startribune.com