SAN FRANCISCO — Frank Gore scored on a 1-yard run and topped the 1,000-yard mark for the fourth straight year, and the San Francisco 49ers moved within one win of avoiding a seventh straight losing season by beating the Detroit Lions 20-6 Sunday.

Alex Smith threw a touchdown pass to Vernon Davis and the Niners (7-8) forced six turnovers to close out the home season with a victory. San Francisco was eliminated from playoff contention with a loss last week at Philadelphia, but still can end its string of losing seasons by winning at St. Louis.
Drew Stanton struggled in his first career start for the Lions (2-13), throwing for just 130 yards and three interceptions before being pulled for Daunte Culpepper midway through the fourth quarter. Detroit lost its fifth straight game and 20th in a row on the road, failing to score after the first drive of the game.
Stanton replaced Culpepper last week as the Lions search for a quarterback with starter Matthew Stafford sidelined with a shoulder injury.
San Francisco didn’t fare much better until getting a pair of touchdowns in the third quarter to pull away from the Lions. The first came when Smith rolled out on third-and-goal from the 2 and flipped a pass to Davis just before crossing the line of scrimmage. It was Davis’ 12th touchdown catch of the season.
On the next drive, Smith found a wide-open Gore on fourth-and-1. Gore scampered to the 6 on a 48-yard gain. Two plays later, he dived in from the 1 to make it 20-3.
Gore ran for 71 yards on 28 carries, topping the 1,000-yard mark earlier in the drive. He has 1,013 yards rushing, becoming the first Niners player to reach 1,000 four times in a career.
Smith went 20 for 31 for 230 yards and his career-high 17th touchdown pass of the season as he tries to solidify his hold on the starting quarterback position heading into next season.
The Lions moved the ball well on their first drive, going 76 yards in 15 plays to set up a 27-yard field goal by Jason Hanson. Detroit had only three more first downs the rest of the half, losing two fumbles and throwing an interception to give San Francisco good field position for much of the half. The Lions didn’t score again until Hanson kicked another field goal late in the fourth quarter long after the game had been decided.
The Niners could not capitalize with points off any of those miscues, each of which gave San Francisco the ball near midfield. Gore was stuffed on fourth-and-1 after Stanton fumbled, the 49ers had to punt after a fumble by Calvin Johnson and Grady Jackson blocked a 28-yard field goal attempt by Ricky Schmitt in the closing seconds of the half.
Schmitt, signed this week to replace injured Joe Nedney, did make a pair of field goals earlier in the half to give San Francisco a 6-3 lead.
NOTES: Lions LB Larry Foote missed the game with a foot injury, ending his streak of 94 straight starts. ... Niners LT Joe Staley left with a bruised knee early in the second half. ... The blocked kick was the 24th by the Lions since the start of the 2001 season, most in the NFL.