CHICAGO – Soldier Field turned back into a house of horrors for the Vikings on Halloween night.

Thanks to a monstrous performance from their rookie running back and a pass rush that spooked Vikings quarterback Sam Bradford, the last-place Chicago Bears stunned the Vikings 20-10, sending them home with their second loss in a row.

Jordan Howard, the 222-pound bruiser the Bears grabbed in the fifth round of this year's draft, piled up 145 yards from scrimmage in the first half against what had been the NFL's top-ranked defense and finished with 153 on the ground Monday night.

The Vikings defense entered the game having allowed a league-low 13 plays of 20 or more yards through six games. They gave up five Monday, four in the first half.

And their leaky offensive line, which was their undoing in last week's 21-10 loss to the Philadelphia Eagles, was beaten for five sacks as the Vikings offense totaled only 258 yards.

"We didn't make any plays," said coach Mike Zimmer, who was more subdued after this double-digit loss than the last. "They made them all."

The alarming loss was the Vikings' 14th in their past 16 games at Soldier Field, leaving their veterans wondering why it has been so tough for them to win in the Windy City.

"I wish I knew the answer to that one," linebacker Chad Greenway said. "We just didn't play good enough tonight."

The Bears grabbed an early 3-0 lead after Howard found a seam in the Vikings defense, then plodded downfield for a nice 69-yard gain. Pro Bowl safety Harrison Smith missed on a diving tackle attempt in the hole, and his rookie counterpart, Jayron Kearse, had a chance to limit the damage but took a bad angle on the run.

Back after missing five games to a sprained thumb on his throwing hand, quarterback Jay Cutler put the Bears (2-6) in position to kick another field goal with a nifty play on third down. He stepped up in the pocket to avoid a blitzing Smith, then flipped a shovel pass to Howard, who rumbled for 34 yards.

"They got lucky on some plays," defensive end Everson Griffen said, mentioning that busted play specifically.

The Bears increased their lead to 13-0 midway through the second quarter. They caught the Vikings (5-2) with a screen pass to Howard on third-and-9, then Cutler hit tight end Zach Miller for a 21-yard gain to move into the red zone. The Bears then simply overpowered the Vikings defense on Howard's 2-yard touchdown run.

Howard was responsible for 202 of Chicago's 403 yards.

"He hit the big one early," Greenway said. "And we didn't counteract that."

The Vikings, whose offense went nearly 20 minutes of action without producing a first down, finally caught the break they needed on a bizarre third-down play where Bradford was hit as he threw, causing him to throw a backward pass.

Chicago defensive end Akiem Hicks had an opportunity to scoop up the loose fumble but was too busy celebrating what he thought was an incompletion. On the sideline, Bears backup defensive end Cornelius Washington also assumed the play was dead, ran onto the field while the play was ongoing and was flagged.

The 15-yard penalty kept the Vikings' drive alive. But after they advanced inside the 5-yard line, Bradford was sacked again on third down, forcing the Vikings to bring out Blair Walsh to kick a 30-yard field goal in the final minute of the half.

After that squandered opportunity, the Bears blew the game open in the third quarter with Cutler's 11-yard touchdown pass to Alshon Jeffery that made the score 20-3.

Despite being down three scores, the Vikings maintained their deliberate approach on offense. They finally found the end zone with just under six minutes left when Bradford threw a 25-yard touchdown pass to Stefon Diggs to pull within 10 points.

But Howard and the Bears hogged the ball the rest of the way to secure their second victory of the season.

"The run defense, especially the fourth-minute defense there at the end, that's inexcusable," Greenway said.

The suddenly-reeling-but-still-in-first-place Vikings, who have lost confidence after starting the season with five straight wins, will get six days to come up with answers after a pair of horrific losses that should quiet Super Bowl talk for the moment.

"We've got to do a lot of things better to be able to get back on track," Griffen said. "We've got nine more games to go. We've just got to keep on going."

Matt Vensel covers the Vikings for the Star Tribune.