San Diego Chargers quarterback Philip Rivers is seen on the sidelines during the fourth quarter of an NFL football game against the St. Louis Rams Sunday, Oct. 17, 2010, in St. Louis. The Rams won 20-17. (AP Photo)
San Diego Chargers place kicker Nate Kaeding walks off the field after having a 49-yard field goal attempt blocked during the fourth quarter. (AP Photo/Jeff Roberson)
St. Louis Rams offensive tackle Gary Gibson, right, and St. Louis Rams defensive end Chris Long, left, sack San Diego Chargers quarterback Philip Rivers (17). (AP Photo/Jeff Roberson)
St. Louis Rams wide receiver Danario Alexander (84) celebrates after holding onto a pass to score a touchdown against San Diego Chargers cornerback Antoine Cason. (AP Photo/Tom Gannam)
St. Louis Rams running back Steven Jackson (39) scores a touchdown against San Diego Chargers free safety Paul Oliver (27) during the the second quarter. (AP Photo/Jeff Roberson)
The Chargers are running out of different ways to lose on the road.
Nate Kaeding slipped and missed a field goal with 8:11 remaining in the fourth quarter that would have cut the St. Louis lead to 17-13.
Instead, the Chargers defense surrendered a field goal on the ensuing drive, which ended up being the difference in the game.
Trailing 20-10, Philip Rivers led the Chargers on a 76-yard scoring drive in just 40 seconds, capped off by a 5-yard touchdown pass to Buster Davis with 3:16 to go.
But that would be the last time the Chargers saw the ball.
On the final clock-killing drive, a powerful Steven Jackson gained 28 yards on five consecutive carries, and rookie quarterback Sam Bradford downed the ball three times in the victory formation to even the Rams record at 3-3.
St. Louis dominated on both sides of the ball against the NFL's top-ranked offense and second-ranked defense, one week after getting blown out 44-6 at Detroit.
Sam Bradford threw a 38-yard touchdown pass to fellow rookie Danario Alexander, making his NFL debut, to help build a 14-point cushion in the first half. Steven Jackson finished with 109 yards and a touchdown for the Rams, who won their third straight at home for the first time since 2004.
Rivers lost his favorite target, tight end Antonio Gates, with a left ankle injury in the first half after getting dinged up blocking on a carry by Ryan Mathews.
Gates finished with two catches for 12 yards, ending his NFL-record run by a tight end with touchdowns in nine consecutive regular-season games.
Malcom Floyd caught just two passes and didn't return after suffering a hamstring injury in the fourth quarter.
Patrick Crayton, who got the starting nod over Legedu Naanee, led the receiving corps with 117 yards on six catches.
Besides a field goal, San Diego's second-half defense halted the Rams' roll. Ron Rivera's squad gave the offense plenty of opportunities to produce. The Chargers defense forced the Rams to go three-and-out in their first two second-half possessions.
Mike Tolbert punched in a one-yard touchdown run behind Devin Hester on the Chargers second possession of the second half.
Present, yet absent, was Shaun Phillips, who tacked on just a single tackle.
Give credit to St. Louis where credit is due. A team that won just one game last year and entered the season on a 14-game losing streak is at .500 with three wins.
They had three wins in the previous two seasons combined.
But there's a point where a slow start to the season is no longer an excuse — the Chargers are at that point.
The Chargers were 2-for-9 in third-down efficiency through the first three quarters and didn't reach the red zone until the 5:53 mark in the 3rd quarter.
The Chargers offensive line featured Pro Bowl left tackle Marcus McNeill, returning for his first game after signing a five-year, $48.5 million contract extension. But McNeill yielded two of the seven costly sacks allowed by the Chargers O-line.
James Hall, Chris Long and Larry Grant had two sacks apiece. Fred Robbins rounded out the Rams' count with one.
It seems as if the Chargers bye in Week 10 cannot come soon enough. To add more fuel to the fire, the Chargers upcoming schedule does not get any easier.
The Chargers host the New England Patriots (4-1) next weekend, followed by pivotal AFC matchups against Tennessee (3-2) and Houston (4-2).