Only one undefeated NFL team remains after the Atlanta Falcons lost to the Buffalo Bills on Sunday. However, there's still a chance we may not see any undefeated teams going into Week 5, as that team (the Kansas City Chiefs) will face the Washington Redskins on Monday Night Football.

Here's a look at some projected Week 5 power rankings following the game, as well as a spotlight on three teams whose rankings deserve further explanation.

Projected Week 5 Power Rankings After Monday Night Football

1. Kansas City Chiefs (4-0)

2. Pittsburgh Steelers (3-1)

3. Green Bay Packers (3-1)

4. Buffalo Bills (3-1)

5. Atlanta Falcons (3-1)

6. Detroit Lions (3-1)

7. Los Angeles Rams (3-1)

8. Denver Broncos (3-1)

9. Carolina Panthers (3-1)

10. Philadelphia Eagles (3-1)

11. Oakland Raiders (2-2)

12. New England Patriots (2-2)

13. Houston Texans (2-2)

14. Washington Redskins (2-2)

15. New Orleans Saints (2-2)

16. Tennessee Titans (2-2)

17. Seattle Seahawks (2-2)

18. Dallas Cowboys (2-2)

19. Cincinnati Bengals (1-3)

20. Minnesota Vikings (2-2)

21. Tampa Bay Buccaneers (2-1)

22. Arizona Cardinals (2-2)

23. New York Jets (2-2)

24. Jacksonville Jaguars (2-2)

25. Baltimore Ravens (2-2)

26. New York Giants (0-4)

27. Chicago Bears (1-3)

28. Indianapolis Colts (1-3)

29. Miami Dolphins (1-2)

30. Los Angeles Chargers (0-4)

31. San Francisco 49ers (0-4)

32. Cleveland Browns (0-4)

Buffalo Bills: No. 4

Why are the Bills, whom no one outside Western New York thought could make the playoffs this year, ahead of all but three teams?

First, the Bills have now given two teams their only losses this season (the Falcons and Denver Broncos).

If quarterback Tyrod Taylor and wide receiver Zay Jones connected on a long fourth-down pass against the Carolina Panthers with just seconds remaining in Week 2, we could be talking about the Bills being 4-0 this year.

However, the pass fell incomplete, and the Bills lost their only game thus far, 9-3.

Second, the defense has simply been sensational, allowing just 13.5 points per game. Notably, they haven't allowed over 17 points during any week this season.

Although the Bills offense, led by Taylor, running back LeSean McCoy and tight end Charles Clay, isn't going to blow anyone away, it gets the job done. A ball-control offense and a stout defense will go a long way this season, and Buffalo may return to the playoffs for the first time since last century.

Dallas Cowboys: No. 18

In our power rankings, the 2-2 Dallas Cowboys are looking up at seven teams with the same win-loss record. This may seem like an odd placement for a team thought to be a Super Bowl contender in the preseason.

However, the Cowboys' resume is not impressive thus far. They have beaten a winless team without their star player (the New York Giants and wide receiver Odell Beckham Jr.) and a .500 team without their star player (the Arizona Cardinals and running back David Johnson). That same Cardinals team was just taken to overtime by the winless San Francisco 49ers at home before a sensational touchdown catch from wideout Larry Fitzgerald saved the day.

In their two other games, the Cowboys were blown out by the Denver Broncos 42-17 and gave up 35 points at home to the Los Angeles Rams.

The Rams are a good team and much improved from last year, but thus far, Dallas just looks OK. In particular, the defense needs to improve in order for the Cowboys to have a shot at the Lombardi Trophy this year.

Cincinnati Bengals: No. 19

The Bengals are ahead of a handful of teams with better win-loss records. Here's why: We can throw the Bengals' first two games out the window at this point and consider them a 1-1 team. Yes, Cincinnati looked awful in losing by a combined score of 33-9, but a change in offensive coordinator has clearly rejuvenated the Bengals.

Since then, Cincinnati has scored 55 points and looks like a different squad.

The Bengals nearly picked off the Green Bay Packers in Lambeau Field, losing 27-24 in overtime after some late heroics from Pack quarterback Aaron Rodgers.

Then, Cincinnati dismantled the Cleveland Browns, 31-7. The matchup wasn't even as close as the score indicated, as Cleveland didn't score its touchdown until after the two-minute warning.

The Bengals defense has been fantastic all season, and it just got linebacker Vontaze Burfict back.

Don't be surprised if the Bengals make a late postseason run, as they have an easier schedule the rest of the way, with home dates against Indianapolis, Cleveland and Chicago.