Seattle, Denver, New England and Kansas City remained unblemished.
The rest of the NFL remained unbelievable.
Cleveland beat Cincinnati? The Browns were supposed to be cooked a couple weeks ago when they traded running back Trent Richardson to Indianapolis and promoted third-string quarterback Brian Hoyer to starter. Now, they've won consecutive games and just knocked off the best team in the AFC North.
Pittsburgh is winless? Yes, the Steelers lost in London to Minnesota, 34-27. It was the first win of the season for the Vikings.
"We are in uncharted territories and the water is dangerous right now," Steelers quarterback Ben Roethlisberger said. "So we have to stick together and get out of it. Right now, you could say we're the worst team in the league. That hurts."
Not so fast. The New York Giants can stake their claim to that title. After Sunday's 31-7 defeat at Kansas City, one Giants player was feeling so adrift he even turned to reporters for a potential remedy.
"If y'all find some answers, let me know," defensive end Justin Tuck said to those gathered around his locker. "I'm willing to try anything and everything."
Anything and everything. That's an accurate description of what happened around the league in Week 4.
Detroit scored four touchdowns and four field goals against Chicago in a 40-32 victory over the Bears. Jay Cutler came into that game with a 7-1 record against the Lions and one interception in those eight games. Sunday, the Chicago quarterback had three interceptions and a fumble.
The Bears rallied down the stretch, but they could never fully recover from giving up so much ground in the first half, when they fell behind, 30-10.
"There are no moral victories, but I thought our guys played tough for the last 30 minutes of that game," Bears Coach Marc Trestman said.
No moral victories? There are certainly morale victories, and that's what San Diego accomplished by beating Dallas at home, 30-21. The Chargers, who typically fold like origami at the end of games, avoided fatal mistakes and outscored the Cowboys in the second half, 20-0.
Like the Chargers, Seattle was similarly, well, half-hearted.
After falling behind in the first two quarters, 20-3, the Seahawks shut down Houston in the second half and collected a major character-building victory. They are notoriously weaker on the road, and they were missing three starting offensive linemen — among them Pro Bowl left tackle Russell Okung and Pro Bowl center Max Unger — and yet Pete Carroll's players got the job done.
The touchdown that forced overtime was a 58-yard interception return by Seattle cornerback Richard Sherman.
Carroll said that on that pick-six "it was like the world stopped for a second there because he had the ball in his hands and no one in front of him, and we had practiced exactly that."
If practice makes perfect, Peyton Manning and the Broncos sure have practiced a lot. In blowing out Philadelphia, 52-20, Denver scored the most points in franchise history and pushed its regular-season winning streak to 15 games, each by at least a touchdown.
Seattle wasn't the only team to dig its way out of a double-digit deficit in the fourth quarter. So did Arizona in its 13-10 victory at Tampa Bay.
The Cardinals trailed, 10-0, in the fourth quarter before rallying. Patrick Peterson had two interceptions in the final period, the first setting up Carson Palmer's 13-yard touchdown pass to Larry Fitzgerald, and the second clinching the victory that sent the Buccaneers to 0-4.
"That fourth quarter was some of the best football we played all year," Cardinals Coach Bruce Arians said.
It has been a decade since Arizona had that type of comeback. The last time they bounced back in the fourth after trailing by 10 points or more was Dec. 28, 2003, against Minnesota.
With four victories, Kansas City has already doubled its 2012 win total. The Chiefs are the second team in NFL history to start 4-0 after racking up at least 14 losses in the previous season. The 1980 Detroit Lions were the first to do so.
"To be honest, all we talked about all off-season was being 1-0," Chiefs quarterback Alex Smith said. "Just get the first one."
And they did. Four times in a row.
A painful turn
Tennessee's Jake Locker threw three touchdown passes in a 38-13 pounding of the New York Jets, but he left the game with a hip injury that landed him in the hospital. The Titans didn't have an update on Locker's condition after the game, but according to The Tennessean, Coach Mike Munchak said the initial exam didn't show that the hip had popped out.
"He was upset. It's emotional," said Munchak, when asked about the quarterback's reaction to the injury.
Ryan Fitzpatrick is the Titans' backup who presumably will be the starter for the time being.
A fine mess
Earlier this season, the NFL cracked down on Tampa Bay safety Dashon Goldson for a dangerous and illegal hit on a defenseless receiver. What began as a one-game suspension was reduced to a $100,000 fine.
Goldson almost certainly will be in hot water again this week as the league reviews another illegal hit, this one on Arizona receiver Jaron Brown.
Buffalo beat Baltimore, 23-20, making the Bills' Doug Marrone and quarterback EJ Manuel the first rookie coach-quarterback tandem to defeat a defending Super Bowl champion since 2003. That's when Jacksonville's Jack Del Rio and Byron Leftwich knocked off Tampa Bay.
Manuel can claim another obscure distinction. He's the first rookie quarterback to beat a reigning champion in the first month of the season.
He'll just take the win.
In throwing four touchdown passes Sunday, Manning carved out another spot in the NFL record books. His 16 touchdown passes — without an interception, mind you — are the most by any player through the first four games of the season.
Every time the Broncos score at home, they celebrate by having their mascot, a horse named Thunder, run around the field.
On Sunday, Manning conceded that Thunder "might have to get an I.V. after that one."
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