The Kansas City Chiefs, Indianapolis Colts, and New England Patriots all had seemingly easy games yesterday, each playing teams that have long since given up on the playoffs. But on a Sunday of surprises, all three games went down to the wire, and only the Patriots emerged victorious.

Indianapolis already has its division all but locked up, but Kansas City’s 31–28 loss to the Cleveland Browns makes a big impact on the AFC playoffs. By falling to 7–5, the Chiefs gave ground in the wild-card race to three teams that improved to 7–5: the Jets, the Cincinnati Bengals, and the Jacksonville Jaguars.

Kansas City seemed to have the game in hand in the fourth quarter, when a 14-play, 99-yard touchdown drive gave the Chiefs a 28–14 lead with less than 10 minutes to play. But the Chiefs began playing a prevent defense, opening the field for Cleveland quarterback Derek Anderson, who replaced injured starter Charlie Frye.

Anderson threw two fourth-quarter touchdown passes, both to tight end Steve Heiden, to tie the game, and he made the key play in overtime with a 33-yard run that moved the Browns into range for Phil Dawson’s game-winning field goal. The Chiefs will long regret allowing 17 straight points to a backup quarterback on a bad team, especially if they miss a playoff spot by one game.

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For the second straight week, a Manning traveled to Tennessee and went home disappointed. Last week it was the Giants’ Eli, who watched a 21–0 second-half lead end in a 24–21 loss to the Titans. This week Indianapolis quarterback Peyton Manning led his team to a 14–0 lead, only to lose 20–17 when Tennessee’s Rob Bironas drilled a 60-yard field goal with seven seconds left.

Manning was his typical self, completing 21 of 28 passes for 351 yards, but his receivers had some costly drops, including a pass that bounced off Marvin Harrison’s hands and into the arms of Titans linebacker Peter Sirmon. Harrison dropped the first two passes thrown to him, although he made up for it the rest of the way, catching seven passes for 172 yards.

Indianapolis demonstrated again that its defense, especially against the run, isn’t good enough to win on days that its offense is anything but perfect. Tennessee had 35 rushes for 219 yards, and Indianapolis constantly struggled to contain Vince Young, the Titans’ rookie quarterback. Young is a talented runner and an improving passer, and the Titans, who started the season 0–5 and are now 5–7, are a talented an improving team.

At 10–2, the Colts still lead the way for home-field advantage in the playoffs, based on a tiebreaker with the 10–2 San Diego Chargers. San Diego also had a close win against a weak opponent, although the Chargers’ 24–21 win over Buffalo wasn’t as close as the score indicated. San Diego jumped out to a 17–0 lead and out-gained Buffalo by more than 100 yards.

LaDainian Tomlinson scored his 26th touchdown for San Diego, leaving him only three shy of a new NFL record, but the biggest story was the return of linebacker Shawne Merriman from a fourgame steroid suspension. Merriman, who had two sacks and two forced fumbles, makes the Chargers — not the Colts — the AFC’s best team.

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For three quarters yesterday, New England quarterback Tom Brady looked frustrated and confused. The Detroit Lions have a terrible pass defense, but they pressured Brady with blitzes and draped his receivers in coverage.

Down 21–13 late in the game, Brady came to life as the Patriots scored two touchdowns to beat Detroit 28–21.

Brady completed 14 of 15 passes for 98 yards in the fourth quarter as New England finally solved Detroit coach Rod Marinelli’s Cover 2 defense with a series of short throws. But while Brady worked out all the kinks by the end of the game, the Lions were able to expose some weaknesses in the Patriots’ defense.

New England almost always shuts down its opposition’s top receiver, but the Patriots often fail to stop passes to no. 2 receivers and running backs. Yesterday, Detroit’s second receiver, Mike Furrey, caught nine passes for 123 yards, and running back Kevin Jones had five catches for 86 yards. The Patriots can beat a team like Detroit without plugging those holes in the defense, but even if Brady keeps coming through in the fourth quarter, they’ll need better pass coverage when the playoffs arrive.

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The NFC playoff picture got a bit clearer when the Chicago Bears became the first team to clinch their division with a 23–13 win over the Minnesota Vikings. But the Bears won in such sloppy fashion that calls for coach Lovie Smith to bench quarterback Rex Grossman will grow louder in Chicago.

Quarterback play doesn’t get much worse than Grossman yesterday. He finished the game 6-of-19 for 34 yards, with three interceptions. For a quarterback to play that badly and still go home with a win, he needs his defense and special teams to control the game, and that’s what Chicago did.

Devin Hester returned a punt 45 yards for a touchdown, Ricky Manning returned an interception 54 yards for a touchdown, and Tank Johnson tackled Minnesota running back Ciatrick Fason in the end zone for a safety. The Bears’ defense made Minnesota quarterback Brad Johnson look almost as bad as Grossman, holding him to 73 passing yards and intercepting him four times before he was benched in the third quarter.

The Bears aren’t the only team that made a statement in the NFC playoff race. Falcons quarterback Michael Vick has faced even more withering scrutiny than Grossman, but he delivered yesterday as Atlanta improved to 6–6 with a 24–14 win over the Redskins.

Although Vick’s passing numbers (8-of-16 for 122 yards) were mediocre, he made it through the game without an interception or a fumble and he gained 59 yards on 10 runs.

Despite his passing flaws, that running ability makes Vick the unofficial league leader in highlight-reel plays. But he may have some competition for that title in the form of New Orleans Saints rookie running back Reggie Bush, who had the best game of his pro career in a 34–10 win over the San Francisco 49ers. Bush caught nine passes for 131 yards and a touchdown, and he added three scores on the ground. Much like Vick, Bush is too inconsistent — even after yesterday’s big game, he still averages just 3.1 yards a carry — but Bush and the 8-4 Saints will be a major part of the playoff race.

Mr. Smith is a contributing editor for FootballOutsiders.com.