Predictably, the Bears' feeble run defense was again trampled, with Adrian Peterson delivering 211 of the Vikings' 246 rushing yards.

And yet, even with all of Peterson's productivity, the defense still had a chance to finish off the win with the Vikings down three and facing fourth-and-11 from their own 9 with 1:55 left.

One stop and the Bears leave the Metrodome for the final time in good spirits. Instead, Vikings quarterback Matt Cassel — playing because Christian Ponder left the game at halftime with a concussion — drilled a 20-yard completion over the middle to Jerome Simpson.

"I mean, I was there," cornerback Tim Jennings said. "He made a good throw low and away. (Simpson) made a play and I didn't. I've got to figure out a way to get there a step sooner."

That missed opportunity will certainly disturb the Bears as they use film study to deliver an autopsy report on Sunday's loss. And that fourth-down hiccup was followed by more Cassel magic — another dart to Simpson for 24 yards; an out route to tight end John Carlson for 17 yards; a timely 21-yarder to a sliding Jarius Wright along the right sideline.

Walsh's 30-yard field goal with 20 seconds left tied the game.

Cassel threw for 243 yards after halftime, including a 7-yard fourth-quarter TD pass to Greg Jennings.

With tiebreakers mixed in, the 6-6 Bears essentially fell two games behind the NFC North-leading Lions (7-5) with four games left.

So much of Sunday's final result hurt.

"Disappointed, obviously," quarterback Josh McCown said. "Very disappointed."

So little made sense.

"Too many highs and lows, man," Jermon Bushrod said. "We had our opportunities. But we put ourselves in a few bad positions. And we came up short, man. It sucks. We work too hard for this."

Twitter @danwiederer