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 6-yard line in the final minute for a 21-14 victory Monday night.

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 4. But a pass was incomplete, Darren Sproles lost 2 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 2-yard TD pass following a San Diego turnover.

Rivers found Antonio Gates with a 3-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.

Ryan Mathews, who is replacing perennial Pro Bowler LaDainian Tomlinson in the Chargers' backfield, took a brutal hit by Derrick Johnson and lost the ball. Brandon Carr scooped it up and ran 16 yards to the San Diego 12 and Cassel made it 14-7 with a 2-yard TD pass to rookie tight end Tony Moeaki.

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 KC on top 21-7 late in the half. The return broke Dante Hall's team record by one yard.

Legedu Naanee of the Chargers got wide open on an obviously blown coverage and hauled in a 59-yard touchdown pass to make it 21-14 with 2:23 left.