The Chiefs and Chargers entered Sunday optimistically harboring playoff hopes.
When their game ended, so did their seasons.
Kansas City rolled to a 19-7 victory that eliminated San Diego from contention, but the Chiefs failed to get the help they needed to qualify.
Baltimore and Houston both needed to lose in games happening at the same time, and both rallied in the second half for wins.
That allowed the Ravens to claim the AFC's final wild-card spot.
Justin Houston had four sacks for the Chiefs (9-7) to break Derrick Thomas's franchise record with 22 in the season. Cairo Santos kicked four field goals, and Chase Daniel played serviceably in place of injured quarterback Alex Smith, throwing for 157 yards without an interception.
The Chiefs' only touchdown came when wide receiver Dwayne Bowe fumbled inches shy of the goal line early in the second quarter. Tight end Travis Kelce recovered in the end zone, not only giving Kansas City a 10-0 lead but keeping a dubious streak intact: No Chiefs wide receiver caught a TD pass all season, the first time in at least 50 years that has happened.
Philip Rivers had 291 yards passing for the Chargers (9-7), going 4,000 yards in a season for the sixth time in his career. Branden Oliver ran for 71 yards and a touchdown.
The Chargers will look back on its season finale as one of wasted opportunities.
Nick Novak missed a 52-yard field goal attempt late in the third quarter. Midway through the fourth, a touchdown pass to Eddie Royal was overturned by a video review when the ball appeared to skip off the turf - San Diego went for it on fourth down and Rivers threw an incomplete pass. Then with about 4 minutes left, Donald Brown was stuffed on fourth-and-1 at the Chiefs 20.
Rivers was intercepted for a second time in the closing seconds of the game.
It appeared for a while that an unexpected series of events just might allow Kansas City to sneak into the playoffs, similar to what happened on the final day of the 2006 season.
The Chiefs had already built a 19-3 lead on a cold day at Arrowhead Stadium. Cleveland was clinging to a 10-3 lead over Baltimore, and three-win Jacksonville led Houston 17-14.
Photos from the Chiefs Week 17 matchup against the Chargers
If all three scores had held, the Chiefs would have claimed the final wild-card spot.
Instead, the Texans took the lead a few minutes later. So did the Ravens. And when both held on to spoil the Chiefs' party, an inspired performance by their defense became moot.
Kansas City started the season 7-3, but limped to the finish amid an avalanche of injuries. The latest was to Smith, who lacerated his spleen in last week's loss to Pittsburgh.
Even if the Chiefs made the playoffs, he likely would have been out until the Super Bowl.
Injuries also crippled San Diego's postseason hopes.
After starting the game without running back Ryan Mathews, wide receiver Keenan Allen and center Chris Watt, the banged-up Chargers watched right tackle D.J. Fluker walked slowly to the locker room late in the first half. He joined safety Marcus Gilchrist (elbow), cornerback Shareece Wright (head injury) and wide receiver Eddie Royal, who got hurt late in the game.
The Chargers wound up losing three of their final four games. They also lost both games to Kansas City, the first time they'd been swept in the season series since the 2003 season.