We saw some favorites suffer shocking defeats in Week 4 of the 2012-2013 NFL season, including the Detroit Lions and the rising Seattle Seahawks.
So what can we expect in Week 5?
There are several matchups that figure to test favorites this week. Heck, some favorites may even lose.
Here are my predictions for Week 5.
Arizona Cardinals (at St. Louis Rams)
While the Arizona Cardinals have proven to have a much-improved defense this season, there are still issues with the offense, which means most games (even wins) should be close.
While the Cardinals blew out the Philadelphia Eagles in Week 3, they also beat the Seattle Seahawks, New England Patriots and Miami Dolphins by a combined nine points, and they averaged 21.3 points in those games.
The run offense of the Cardinals needs some work, and Arizona is happy as long as quarterback Kevin Kolb simply manages the game. Against a tough pass defense in St. Louis which has allowed 6.8 yards per attempt while giving up just two passing touchdowns, this one could go down to the wire.
Still, I see Arizona barely edging the Rams in Week 5.
Prediction: Cardinals 20, Rams 17
Pittsburgh Steelers (vs. Philadelphia Eagles)
I know Pittsburgh is playing at Heinz Field, but the 34-31 loss against the Oakland Raiders in Week 3 was particularly concerning.
There is no question that the Steelers defense has gotten older and slower, and that has shown in both the run defense and the pass defense.
After seeing speedy Denver Broncos receiver Demaryius Thomas come back to haunt the Steelers in Week 1, Oakland Raiders running back Darren McFadden went off for 113 yards and a touchdown on 18 carries in Week 3.
Obviously, Michael Vick needs to worry about taking care of the ball, but he was much better in that department against the swarming New York Giants last week, and the Steelers have only forced three turnovers, so far (one interception, two fumbles).
Prediction: Eagles 30, Steelers 24
New Orleans Saints (vs. San Diego Chargers)
Which favorite should be most concerned heading into Week 5?
There's a reason the Saints are 0-4 this season, and it's not the offense.
The Saints have scored 27.5 points per game this season (10th in the NFL) but have allowed 32.5 points per game (29th). Given the Chargers just dropped 37 points against the Kansas City Chiefs last week, you can expect San Diego to unload on New Orleans in Week 5.
You add the fact that the Chargers pass defense has actually been pretty good this season (allowing 6.3 yards per attempt) and I see San Diego pulling this one out in Louisiana.
Prediction: Chargers 30, Saints 24