ALLEN PARK, Mich. -

For Matthew Stafford and the Detroit Lions, this was another missed opportunity.

With a chance to take over sole possession of first place in the NFC North -- and offer perhaps the strongest evidence yet that they belong among the NFL's elite -- the Lions had a hard time putting the ball in the end zone against San Francisco's tough defense in a 27-19 loss to the 49ers on Sunday night.

Last season, the Lions won 10 games, but none of their victories was against a team that finished above .500. This season seems to have started with a similar pattern: Detroit edged St. Louis in the opener before losing on the road against the playoff-tested 49ers.

"We didn't play our best game really in any phases," Stafford said. "I'm proud of our guys for fighting and staying in there, but we've got to put some effort into coming out and trying to play a little bit better."

For a Detroit team hoping to take another step forward after making the playoffs a season ago, four field goals and a late touchdown wasn't much to brag about. Stafford went 19 of 32 for 230 yards with a touchdown and an interception. That was after throwing three interceptions against the Rams.

Calvin Johnson caught eight passes for 94 yards, but San Francisco didn't allow him to make any game-breaking plays. In all, the explosive Lions looked ordinary on offense against the 49ers for the second straight year.

San Francisco won at Detroit in 2011.

"They're a good defense. They're well coached, well disciplined," Johnson said. "They're doing what they're supposed to do out there. We just have to be patient. I feel like we were patient in the second half. We were doing some good things. We just have to get that ball in the end zone."

The Lions play at Tennessee on Sunday.

"This felt as if it was a playoff game," Lions coach Jim Schwartz said after the loss to San Francisco. "It's two teams that have high expectations that are good teams coming in, Sunday night game and everything else. But let's face it, it's not a playoff game. We have to play again next week. The teams that are going to do well are the teams that can negotiate the highs and lows in this league."

The Lions might get a boost with the return of running back Mikel Leshoure. It's actually not really a return, because Leshoure has never played an NFL game, but he's set to make his debut after missing all of last season with an injury and the first two games this season on a suspension.

"We've been waiting to see him for a long time. We drafted him in the second round," Schwartz said. "He was showing us all things we needed before his rookie year when he got hurt."

Leshoure missed his rookie season with a torn Achilles tendon. Then came the suspension for violating the NFL's substance-abuse policy. He's eligible to play now -- just as Schwartz seems to be growing less enamored with his team's running game.

Kevin Smith was held to 53 yards on 16 carries Sunday.

"We do need to run the ball a little bit better," Schwartz said. "Hopefully Leshoure can be a big part of that."

Defensively, Detroit managed three sacks but also allowed the 49ers to convert three big third downs on a touchdown drive that made it 27-12 in the fourth quarter.

The Lions were without defensive backs Chris Houston (left ankle), Louis Delmas (left knee) and Bill Bentley (concussion). Schwartz said Delmas' recovery is trending in the right direction.

"But how quickly and whether he'll be back, only this week will be able to tell us," he said. "He continues to make progress, but we'll just wait and see this week."