Shaun Hill passed for 197 yards and a touchdown and ran for another score in his first NFL start, and the San Francisco 49ers beat the Cincinnati Bengals 20-13 tonight for just their second victory in 12 games.

Frank Gore rushed for a season-high 138 yards, and Darrell Jackson had a season-high eight catches for 86 yards in a surprisingly effective San Francisco (4-10) attack led by Hill, a six-year veteran backup who only threw his first NFL passes last week after Trent Dilfer got a concussion.

With Alex Smith also sidelined, Hill was the only quarterback left in San Francisco — and he improbably sparked the 49ers' league-worst offense to the club's first home victory since opening week. Hill went 21-of-28, hitting Vernon Davis with a precise TD pass 9 seconds before halftime and generally running the show with confidence.

Cincinnati's Carson Palmer threw his 100th touchdown pass, a 52-yard strike to Chris Henry in the first half, to become the fifth-fastest passer in NFL history to reach the mark. Palmer passed for 252 yards, but last season's Pro Bowl MVP couldn't rally the Bengals (5-9) to a tying score — not after Chad Johnson dropped a difficult fourth-down catch in the end zone with 2:14 left.

Hill, whose last start was for NFL Europe's Amsterdam Admirals in 2003, completed nine of his first 10 passes for 84 yards on the 49ers' first two drives. San Francisco finished with 337 yards — its second-best offensive game all year — and matched its highest point total in a home game this season.

San Francisco's successes are Cincinnati's woes in one of the Bengals' most embarrassing losses of coach Marvin Lewis' five seasons. Cincinnati, which hasn't won consecutive games all season, is assured of its first losing record since 2002.

The franchises met in two Super Bowls, with the 49ers winning both. Both teams are out of playoff contention this season, and the vibe was appropriately muted early on at chilly Candlestick Park for the Bengals' first visit since 1996.

But after spending most of the season dead last in many offensive statistical categories, the 49ers looked downright competent from their opening 76-yard drive. Hill finished it with a perfect 3-yard bootleg, outrunning safety John Busing to the corner of the end zone.

The touchdown gave San Francisco its first lead at home since its season-opening victory over Arizona.

Cincinnati went ahead 10-7 when Henry got behind two defenders for his TD catch late in the first half, but Hill rallied the 49ers again on another long drive capped by an impressive 17-yard throw to Davis in coverage. Davis, the athletic tight end often underutilized by Smith and Dilfer, celebrated by jumping into the crowd as the 49ers earned their first halftime lead of the season.

Joe Nedney added two field goals in the third quarter while the San Francisco defense stayed strong, but 49ers coach Mike Nolan passed up the chance to kick a 42-yard field goal with 6:15 to play, instead failing on a fourth-down conversion attempt.

The Bengals' T.J. Houshmandzadeh set the franchise record with his 101st reception on a fourth-down conversion as Cincinnati moved to the 49ers 24. But Johnson couldn't hold on to a fourth-down pass in the end zone with 2:14 to play, failing to gather the precise pass to his body as he fell out of bounds.