After three quarters Sunday at Soldier Field, the Bears appeared to be in prime position to snap their three-game losing streak with a victory over the first-place Detroit Lions.

Behind quarterback Jimmy Clausen—who was making his first NFL start in four years—and a strong defensive effort, the Bears carried a 14-10 lead into the final period.

But as has been the case throughout a disappointing season, costly mistakes led to yet another loss. This time, the Bears were outscored 10-0 over the final 7:15 of the game in falling 20-14. They've now lost four straight and seven of nine since they were 3-3.

"I've said this far too many times over the last few weeks—we have a disappointed locker room in there," said coach Marc Trestman. "Nobody in there is comfortable with the results of this game."

Trestman acknowledged that he's in the midst of the toughest stretch of his coaching career.

"I think it all comes down to the effort that the players are making to try to make it right and not to be able to see it get done on Sundays," he said.

The key play came midway through the fourth quarter when Tim Jennings drew a 46-yard pass interference penalty against receiver Corey Fuller on third-and-10, giving the Lions a first down at the Chicago 17. On the next play, Joique Bell's 17-yard touchdown run gave Detroit a 17-14 lead.

After the Bears went three-and-out, the Lions extended their lead to 20-14 on Matt Prater's 30-yard field goal with 2:35 remaining. The Bears then took over at their own 21 and advanced to their own 45. But Clausen's pass on third-and-10 was dropped by Alshon Jeffery and a desperation heave on fourth-and-10 was intercepted by safety Glover Quin at the Detroit 25.

The late interception was Clausen's only turnover of the game. In his first start in place of Jay Cutler, Clausen rebounded from a slow start to give the Bears a 14-10 lead with touchdown passes of 11 yards to Kyle Long late in the first half and 20 yards to Jeffery early in the second half.

Through three quarters, Clausen had completed 19 of 29 passes for 156 yards, two touchdowns and a 102.1 passer rating. But he finished with a rating of 77.0 after connecting on only 4 of 10 passes for 25 yards and an interception in the final period.

"Overall I think we moved the ball like we wanted to," he said. "But at the end of the day we didn't come up with the victory, and that's the ultimate goal and the only thing we were worried about."

Both Bears touchdowns came after huge special teams blunders by the Lions.

First, Jeremy Ross muffed a punt and Sherrick McManis recovered the loose ball at the Detroit 11, leading to Forte's TD on the next play. Early in the second half, a roughing-the-punter penalty on fourth-and-23 sustained a Bears drive that resulted in Jeffery's touchdown.

The Bears defense played a strong first half, holding the Lions to seven points while recording four sacks of Matthew Stafford and intercepting two of his passes in the red zone.

Stafford's 53.7 passer rating in Sunday's game was less than half the 116.0 he posted in a 34-17 win over the Bears on Thanksgiving Day at Ford Field in Detroit.

The loss in their final home game assured the Bears (5-10) of their first double-digit losing season since they went 5-11 in 2004. They will conclude the season next Sunday in Minnesota against the Vikings (6-9) with the winner finishing third in the NFC North and the loser in last place.

"There are no moral victories in football," defensive end Jared Allen said after Sunday's defeat. "We lost. Defensively, we gave up a drive to do it. It's one of those games you can't give that up. We missed some tackles and they ran the ball in. We had a couple penalties.

"When you're in these kinds of games, little things will shoot you in the foot. We took the ball away, but it just wasn't enough today. We all have to make plays to win games."