So are the New Orleans Saints, who survived another nail-biter on Sunday to join them in their run to a perfect season.
After throwing three early TDs, then three interceptions, Manning led the Colts (13-0) on a late TD drive to put Denver away 28-16. The Colts set NFL records with their 22nd consecutive regular-season win and their 114th this decade to wrap up home-field advantage throughout the AFC playoffs.
It was quite a day in Indy, which broke New England's regular-season mark set last year. The Colts became the seventh team in league history to start 13-0, including this year's Saints.
Indy's victory broke a tie with the 1990s San Francisco 49ers, who won 113 wins, and set a franchise record with its 13th consecutive home win.
"When you think about how many we have won these two years, you do take a minute to think about it, and it does kind of hit you — that's a bunch," Manning said. "This was a tough team. This was a great mental challenge."
Denver (8-5) also had a record day. Receiver Brandon Marshall set the league's single-game record with 21 receptions. He finished with 200 yards and two touchdowns, tying the reception record on a 5-yard TD catch with 9:44 left in the game to make it 21-16 and broke the mark on the Broncos' final play.
Drew Brees kept the Saints unbeaten, throwing for 296 yards and three touchdowns, Jonathan Vilma came up with two huge defensive plays, and the Saints pulled out another tight win, 26-23 over the Atlanta Falcons.
New Orleans struggled to hold off a 6-7 Atlanta team that was missing injured stars Matt Ryan and Michael Turner. The result was in doubt until Vilma came up with a crushing fourth-down hit on Jason Snelling, stopping him a yard short of the marker with just over a minute remaining.
The Saints remained unbeaten though the last two wins have been by the closest margins of a season dominated by double-digit wins.
"Why would we be concerned? We're 13-0," Vilma said. "You're not going to get many blowout wins in the NFL."
Or, as Brees said, "We call that being battle-tested."
While lacking in style points, New Orleans set a franchise record for wins in a season, clinched a first-round bye in the playoffs and moved a step closer to home-field advantage throughout the NFC playoffs.
Peterson added 40 yards receiving and set a single-season team record with 14 rushing touchdowns, moving the Vikings (11-2) within one more win of a second straight NFC North title. Brett Favre completed 17 of 30 passes for 192 yards, one touchdown and an interception.
Cincinnati's Carson Palmer was 15 for 25 for a season-low 94 yards and one touchdown, and Cedric Benson's 16 carries for 96 yards gave him his first 1,000-yard season but left the Bengals (9-4) short of 100 for the first time in a month.
The second-year wide receiver missed last week with a concussion, but was in sensational form in boosting Philadelphia (9-4) into the NFC East lead. Jackson has eight touchdowns of 50-plus yards this year, tying the NFL mark.
New York (7-6) also had its share of big plays, including TD passes of 68 and 61 yards by Eli Manning in a game marked by shoddy tackling on both sides. But the Eagles, whose previous high in 2009 was 40 points in a Nov. 1 rout of New York, prevailed despite being outgained 512-374.
Johnson had a season-high 193 yards receiving and two touchdowns to lead Houston (6-7) over Seattle (5-8), breaking a four-game losing streak.
Schaub had 336 yards passing before halftime and finished with 365 yards and two touchdowns. His first-half yardage was the second-most in a first half this season in the NFL.
Seattle's Matt Hasselbeck had three fumbles, was sacked three times and taken down numerous other times and finished with 247 yards passing.
The Bears (5-8) lost for the seventh time in nine games.
Baltimore (7-6) built a 20-3 halftime lead behind the play of Rice, who had 155 yards rushing on only nine carries, and four catches for 53 yards. His 59-yard touchdown run made it 17-3, and the Ravens cruised to the finish in handing the hapless Lions (2-11) their 19th straight road loss.
The Patriots (8-5) snapped a two-game losing streak and maintained their one-game lead in the AFC East. The Panthers (5-8) lost for the third time in four games.
The Patriots lost two fumbles and an interception before Brady's pass to Watson broke a 7-7 tie, and Stephen Gostkowski kicked field goals of 48 and 47 yards in the fourth quarter.
The Bills (5-8) overcame three turnovers and an ineffective passing game to finally close out a win in the fourth quarter. Buffalo lost seven previous times this season when they were within a touchdown headed into the final 15 minutes, but pulled this one out with two interceptions in the final 2:11.
Kansas City (3-10) got a career-high 143 yards and a touchdown from Jamaal Charles, but couldn't overcome another shaky game from Cassel, who threw three interceptions in the fourth quarter.
At Tampa, Fla., Thomas Jones ran for 99 yards and two touchdowns, Jay Feely kicked four field goals, and the New York Jets intercepted rookie Josh Freeman three times while holding the sputtering Bucs to 135 yards.
Filling in for injured rookie quarterback Mark Sanchez, Kellen Clemens completed 12 of 23 passes for just 111 yards. Receiver Brad Smith had the Jets' longest completion of the day — 27 yards — when he threw to Eric Smith on a fake punt play.
The Jets (7-6) climbed over .500 for the first time since Oct. 25. The Bucs (1-12) lost for the third straight week to a backup quarterback.
The loss snapped the Jaguars' five-game winning streak at home, and now Jacksonville (7-6) no longer control its wild-card hopes.
Miami (7-6), which won its sixth consecutive game decided by seven points or fewer, stopped David Garrard on fourth-and-3 with 1:20 remaining and then sacked him on the final play to seal the victory.
The Chargers (10-3) won their eighth straight and are on the verge of a playoff berth. San Diego also won its 16th straight in December, all with Rivers.
Dallas coach Wade Phillips fell to 3-8 in December with the Cowboys (8-5). They have dropped consecutive games for the first time this season.
The Titans (6-7) must win out and get plenty of help after their 0-6 start. But they started a three-game homestand by handing the struggling Rams (1-12) a fifth straight loss even with Vince Young sidelined by a strained right hamstring most of the game.
Johnson, the NFL's leading rusher, set a couple of franchise records. His 17-yard run at the end of the first half pushed him past Hall of Fame running back Earl Campbell's mark of 1,981 yards from scrimmage in 1980. Johnson also has the team mark to himself with eight straight 100-yard rushing games.
The Redskins (4-9) had lost three straight, blowing leads of six, eight and 10 points, before beating the Raiders (4-9).
JaMarcus Russell, who lost his job last month after completing just 46.8 percent of his passes and committing 14 turnovers, entered to start the third quarter for Oakland after Bruce Gradkowski left with partially sprained ligaments in both knees.