SAN FRANCISCO — A week after getting knocked out of playoff contention, San Francisco started slowly against Detroit.

The 49ers put it together in the second half to move one step closer to their only big goal left — avoiding a seventh straight losing season.

Frank Gore scored on a 1-yard run and topped the 1,000-yard mark for the fourth straight year, and the 49ers took advantage of six turnovers to beat the Lions, 20-6, yesterday.

Alex Smith threw a touchdown pass to Vernon Davis and the Niners scored both their touchdowns in the third quarter to close out the home season. San Francisco (7-8) needs to win at St. Louis next week to finish at .500.

"I think it's a matter of pride," Smith said. "It's what we're playing for right now. We haven't finished better than 7-9 since I've been here. It's something we're all playing for."

San Francisco finally got things going in the third quarter. The first touchdown 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, which made it 13-3.

On the next drive, Smith found a wide-open Gore on fourth-and-1. Gore scampered to the 6 for a 48-yard gain. Two plays later, he dived in from the 1.

"The bottom line is we came out in the second half and picked it up and got going and began to execute and created some things," 49ers coach Mike Singletary said.

Gore ran for 71 yards on 28 carries.

Drew Stanton struggled in his first career start for Detroit (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.