Kansas City, Mo. ? Jamaal Charles’ 56-yard touchdown run and Dexter McCluster’s team-record 94-yard punt return gave Kansas City a two-touchdown lead, and the Chiefs held San Diego on four downs inside the six-yard line in the final minute for a 21-14 victory Monday night.

Kansas City wide receiver Dexter McCluster (22) runs 94 yards for a touchdown on a punt return. It proved to be the difference as the Chiefs held off the Chargers, 21-14, on Monday in Kansas City, Mo.

Playing most of the game in a pounding rain, the Chiefs turned the night into the confidence-building coming-out party they had been hoping for since the schedule came out in April. By beating the four-time defending AFC West champions, they proclaimed an end to a three-year period that was one of the darkest in team history.

Philip Rivers thoroughly outplayed Chiefs quarterback Matt Cassel and drove the Chargers to a first-and-goal from the four. But a pass was incomplete, Darren Sproles lost two yards, and another pass sailed high. Then with 39 seconds left, Rivers missed again. The rain-soaked crowd, which hadn’t seen the Chiefs win on Monday night in 10 years, erupted in cheers.

Rivers was 22-for-39 for 298 yards and two touchdowns, several times victimizing a young Chiefs secondary for long gains. Cassel, with a history of playing poorly against the Chargers, was 10-for-22 for 68 yards, including a two-yard TD pass following a San Diego turnover.

Rivers found Antonio Gates with a three-yard TD pass on San Diego’s second possession for the game’s first score.

But as lightning flashed overhead, the Chiefs struck quickly to make up for an otherwise impotent offense in Arrowhead Stadium’s first Monday night game in six years.

After Kansas City’s first two possessions produced nothing, Charles, a 1,000-yard rusher who was beaten out in training camp by veteran Thomas Jones, broke through a hole and sped 56 yards with 37 seconds left in the first quarter to tie the game.

McCluster, a scatback who was a training camp sensation with his quickness and flair, took a San Diego punt in heavy rain in the second quarter and cut left. He sailed almost untouched down the sideline and got the only block he needed from Andy Studebaker in a 94-yard return that put K.C. on top, 21-7, late in the half. The return broke Dante Hall’s team record by one yard.