Chargers head coach Norv Turner, a Bay Area native who spent last season as offensive coordinator in San Francisco, removed most of his starters early. Third string quarterback Charlie Whitehurst completed 7-of-14 passes for 76 yards and a touchdown and Eldra Buckley carried 18 times for 56 yards for San Diego (3-1), which opens the regular season September 9 against Chicago.

Joe Nedney booted a pair of field goals and Zach Hilton caught a 21-yard touchdown pass from third-stringer Shaun Hill, who finished 14-for-29 for 124 yards passing with three interceptions for the 49ers.

Alex Smith played four series and had turnovers on his last two -- an interception by Clinton Hart in the first quarter and a fumble recovered by Jacques Cesaire later on. Smith finished 3-of-8 for 23 yards.

Thomas Clayton carried 14 times for 84 yards, and Delanie Walker had four receptions for 45 yards for San Francisco (1-3), which opens its season Monday, September 10 against the Arizona Cardinals.

The Chargers got on the board with a pair of Kaeding field goals, the first a 29-yarder with 40 seconds remaining in the first quarter.

Kaeding's second, a 22-yard effort, split the uprights at 12:42 in the second to make it 6-0.

The 49ers finally got on the board with a 28-yard Nedney field goal, but their offensive woes continued.

Hill's pass attempt went off the hands of Walker and was picked by Paul Oliver, who returned it nine yards with 2:43 to go in the third.

Andrew Pinnock gained seven up the middle, then found another hole for a four- yard gain and a first down at the two-minute warning. Whitehurst followed by hitting Davis with a 40-yard touchdown with 1:53 remaining. The play was reviewed -- and upheld -- after officials determined Davis was not down before crossing the goal line. That score gave San Diego a 13-3 edge at halftime.

Both sides exchanged field goals in the fourth quarter, with Nedney booting a 48-yarder and Kaeding answering with a 29-yard effort to make it 16-6.

San Francisco's Hilton hauled in a 21-yard pass from Hill with 6:34 remaining, capping a nine play, 75-yard drive.