A haunting Halloween howler by San Diego Chargers quarterback Philip Rivers helped the Kansas City Chiefs steal an improbable 23-20 overtime victory and move into joint control of the AFC West on Monday.

Rivers fumbled a snap with a little over a minute left in the fourth quarter and his team in position to kick a game-winning field goal. The game went into overtime and the Chiefs won it with a field goal of their own.

Kansas City drove their first overtime possession 69 yards and Ryan Succop slotted the winning kick that gave the Chiefs (4-3) their fourth straight victory and tied them with the Chargers (4-3) at the top of the division.

Unbelievable. Our guys continued to battle, we win it and now we're all tied up for first, Kansas City quarterback Matt Cassel told reporters, having helped his team climb out of an 0-3 start to the season.

Before (the fumble) it looked a little glum for us. Our guys were able to overcome tonight.

San Diego have now lost two straight in heartbreaking fashion after the team blew an 11-point lead against the New York Jets last week.

Kansas City established early control on Monday by taking a 13-3 halftime lead as Rivers threw two first-half interceptions before rallying his team in the second half and finishing with 369 passing yards.

Nick Novak booted three field goals in the third quarter to pull the Chargers within a point at 13-12.

The Chiefs stretched their lead with a one-yard touchdown run from Jackie Battle in the fourth, but Rivers drove the visitors 80 yards for a touchdown and a two-point conversion that tied the contest at 20-20 with 7:11 left in regulation.

San Diego were again driving down the field and had reached Kansas City's 15 when Rivers mishandled the snap on first down and the Chiefs recovered possession.

It looked to me like Philip got a little anxious and came out early, but it's hard to tell, Chargers coach Norv Turner said. We were in position to kick the game-winning field goal and it didn't happen.

After racing out to the early lead, the Chiefs offense sputtered for large parts of the game but they were sparked back to life in the fourth by Battle, who finished with 70 yards. Cassel threw for 261 yards and one first-quarter score.