AP

Philip Rivers stood on the sideline watching the Chiefs’ final drive Monday night, just starting to fully realize that this was a game, a mistake he would never forget.

“Worst day ever,” Rivers mouthed to no one in particular.

That was before Rivers watched Chiefs kicker Ryan Succop split the uprights in overtime to complete a wild 23-20 overtime victory that changed the entire complexion of the AFC West.

Just minutes before Rivers said those words, it looked like he would be celebrating a terrific fourth quarter comeback. San Diego, led by running back Curtis Brinkley of all people, was in position to run the clock out before attempting a short field goal to win the game. And then Rivers fumbled a snap with under a minute remaining.

This was the Miracle at Arrowhead. (Seriously, we need a nickname for this play. We’re rolling with “The Phumble” for now. Leave your ideas in the comments.)

Unlike Joe Pisarcik back in 1978, Rivers got a chance to make amends with a possession in overtime. The Chargers won the coin toss, but Tamba Hali sacked Rivers to help force a three and out.

Hali had an incredible night. He recorded two sacks and helped to force Chargers left tackle Marcus McNeill into at least six penalties. For so much of the night, this game was about the Chiefs young core of defensive stars (Hali, cornerback Brandon Flowers, and linebacker Derrick Johnson) making more plays than the San Diego offense.

All we’ll remember years from now is Rivers’ fumble. It was his third turnover on a night where Rivers overcome serious accuracy woes. Despite the problems, Rivers made a number of critical throws in the fourth quarter, often on the move, to put his team in position to win.

It looked like it would be a season-defining win for the Chargers. They weren’t crisp on offense, but they were on their way to “winning ugly” again. They had a chance to bury the Chiefs in the standings. (A two game lead with the tiebreaker.)

Instead, the Chargers’ season is just starting to look ugly.

San Diego is 4-3, in a three-way tie atop the division, and have to host the Packers Sunday in San Diego. The Chiefs, meanwhile, have won four straight and get to host the Dolphins and Broncos the next two weeks.

This doesn’t look like one of Norv Turner’s better Chargers teams. The defense is ordinary, and Rivers doesn’t seem right.

It would be easy to ignore all that if Rivers hadn’t Phumbled. But he did, and it’s a play no one in the AFC West is going to forget all season. Especially Rivers.