SAN FRANCISCO — The San Francisco 49ers may have found themselves another third-round gem at running back.

Four years after picking Frank Gore in that round and watching him develop into a star, the Niners must be happy with what they've seen so far from rookie Glen Coffee, who leads the NFL in rushing this preseason with 196 yards.

Coffee shined in Saturday night's 21-20 victory over the Oakland Raiders, rushing for 129 yards on 16 carries while Gore spent most of the night as a spectator.

"I'm learning to be a physical runner and it's easy behind this line," Coffee said. "They just blocked and blocked and blocked."

And Coffee just ran. He ripped off four runs of at least 10 yards, including a 35-yarder. Coffee said he hadn't seen so many holes since high school.

The Niners have lacked a dependable backup to Gore in recent years. DeShaun Foster got only 21 carries over the first 12 games last year before getting a chance when Gore went down with an ankle injury late in the season.

The previous two years, fullback Michael Robinson had the most carries of any other back, with 26 in 2007 and 38 the previous year.

Gore will once again get the bulk of the carries, but with coach Mike Singletary vowing to rely on a power running game, there should be plenty of opportunities for Coffee if he keeps playing like this.

"Frank Gore is, in my opinion, one of the top five backs in the league," Singletary said. "Frank's going to run the ball. We're going to get the ball to Frank. Coffee, we're very thankful that we have him, but he's going to serve the same purpose that we brought him here for. There's going to be times when Frank needs a rest, and that's when Coffee will have a chance to play."

The Niners had a hard time giving Gore a rest in recent years and the wear and tear showed up in his late-game performances. In the fourth quarter, he averaged only 2.8 yards per carry last season.

Gore likes what he has seen so far from his newest backup. Coffee played the entire first half of the exhibition opener against Denver, rushing for 67 yards on 14 carries.

After Gore played one series against Oakland, gaining 7 yards on two carries, Coffee was even better than in his debut as he finished out the half.

"He's doing a great job, running strong, finding the holes," Gore said. "Glen's going to be a great player."

Gore lasted until the third round in the 2005 draft because he underwent who two reconstructive knee surgeries in college. He ran for 608 yards as a rookie before leading the NFL with 1,695 yards rushing in 2006.

He was slowed a bit by injuries the past two seasons, running for 1,102 yards in '07 and 1,036 last season.

Coffee emerged in his junior season last year after starting only three games his first two years at Alabama. He ranked in the SEC with 1,383 rushing yards last season and opted to skip his senior year and enter the draft.

One of Coffee's newest teammates in the pros was very familiar with what he could do and told him off the bat that he did not like him. A surprised Coffee asked Takeo Spikes why.

"I said, 'Because you used to run all over Auburn,' " said Spikes, a former linebacker with the Tigers. "I used to pay attention to Coffee every Saturday. I was like, 'This guy is a bruiser.' When he got here, I found out that he wasn't as big, but he runs hard and he has a big heart, and that's something you can't measure."