First place in the NFC North division is at stake on Sunday, and the Green Bay Packers will be nowhere in the vicinity.
Instead, it's the Chicago Bears, one of seven 3-0 teams in the NFL, against the Detroit Lions at Ford Field. A victory for Chicago would give it a stranglehold on the division through one-fourth of the schedule.
The Bears have been impressive under new coach Marc Trestman, showing a knack for vital plays on both sides of the ball. They have a league-high 11 takeaways, are making good decisions, and Devin Hester is averaging 38 yards per kickoff return.
But they also have some injuries, with defensive end Henry Melton (knee) gone for the season and star cornerback Charles Tillman hobbled but saying he will play. Tillman normally would match up with the Lions' top threat, receiver Calvin Johnson.
"He's a big, strong, physical corner," Johnson said of Tillman. "He's smart. He's seen a lot of football, so he understands some of the concepts probably that we do on offense, so we've got to throw different things at him to get him off balance."
Detroit is winning the close ones the Lions have outscored the opposition by only 13 points. Their passing attack is second in the league, but just lost a key piece when receiver Nate Burleson was injured in a car accident.
The Lions got some good news: Running back Reggie Bush has recovered from the left knee injury that sidelined him in last week's win over Washington.
"He's a very valuable part of our offense and he affects the way defenses play us," coach Jim Schwartz said. "If we can get him back on the field, that will be a big plus for us."
Under Pete Carroll, the Seattle Seahawks have been dominant at home, but mediocre on the road. They began turning that around late last season, and a win in Houston on Sunday would make a big statement.
Carroll takes the NFL's stingiest defense, particularly against the pass, into Reliant Stadium. Houston also has a rugged defense, but the Texans got pushed around by Baltimore last week and have yet to make their own statement as a power.
The unbeaten New England Patriots visit Atlanta, which is struggling. The Falcons need to get healthy as much as anything, and find ways to stop the pass.
That, of course, is essential against quarterback Tom Brady, whose receiving corps looked far more professional in the romp over Tampa Bay than in the first two wins.
Meanwhile, Monday's compelling matchup between the New Orleans Saints and Miami Dolphins features two teams who had losing records last season and are off to 3-0 starts this time.
Coach Sean Payton's return to the sideline has made a world of difference in the Big Easy, and his hiring of Rob Ryan to run the Saints defense so far has been a stroke of genius.
The Saints rank fourth in overall defense, almost unheard-of territory in New Orleans.
The Dolphins got the first comeback victory of second-year quarterback Ryan Tannehill's career last Sunday over Atlanta.
Week 4 began with the San Francisco 49ers routing the St. Louis Rams 35-11 on Thursday, with running back Frank Gore piling up 153 yards and a touchdown. The 49ers are right back on their feet at 2-2, while the Rams have dropped three in a row since winning the opener.
Also on Sunday, it's Pittsburgh vs. Minnesota in London, the New York Jets at Tennessee, Philadelphia at Denver, Dallas at San Diego, the New York Giants at Kansas City, Cincinnati at Cleveland, Baltimore at Buffalo, Indianapolis at Jacksonville, Washington at Oakland, and Arizona at Tampa Bay.