Vikings coach Mike Zimmer opened his postgame news conference after the Vikings' 33-27 loss to the Bears Sunday with a stat that summarized the difference from a November win in Chicago.
"The last time we played them," Zimmer said, "they didn't score a touchdown on us defensively."
Two of the Bears' three offensive touchdowns on Sunday came on the ground, as running back David Montgomery and mobile quarterback Mitchell Trubisky gouged a Vikings run defense that allowed a season-worst 199 rushing yards, including a career-high 146 for Montgomery.
The Vikings faced neither Montgomery nor Trubisky during last month's 19-13 win at Chicago, where immobile quarterback Nick Foles was shut down and Montgomery was sidelined by a concussion.
"I guess their running back is a big difference," cornerback Cameron Dantzler said. "They didn't have him the first [meeting]. It showed."
The Vikings' injury-riddled defense wasn't suited to handle Chicago's new run-heavy approach.
Minnesota was already down linebacker Eric Kendricks when rookie middle linebacker Troy Dye exited in the third quarter with a concussion. Five plays later, Montgomery breezed up the middle past replacement linebacker Hardy Nickerson Jr. – and through a missed tackle by safety Anthony Harris – during a 14-yard touchdown run to give Chicago a 27-17 lead.
"That 14-yard touchdown run was awesome, because [Montgomery] runs so hard," Bears coach Matt Nagy said. "He's really, really hard to bring down with one guy. He runs with extreme passion. The guys love that. We're feeding off of him."
Montgomery also had a 1-yard touchdown run in the second quarter, off a Bears drive capped by five straight runs. Quarterback option plays with Trubisky, who added 34 rushing yards on eight carries, was another element the Vikings struggled to cover.
Montgomery continually found cutback lanes and poor tackling efforts, according to coach Mike Zimmer.
"They were getting us moving," he said, "and then getting the back side cutting, and it looked like the back was coming out the backdoor. Then we didn't do a good job of tackling him."
The Vikings' middling run defense, which ranked 13th entering Sunday allowing 4.3 yards per carry, will fall further after Chicago's 199 rushing yards -- the fifth most against a Zimmer defense in Minnesota.
Montgomery and Trubisky wore down the Vikings defense quickly, rebounding after an opening three-and-out series with six straight scoring drives – excluding a possession with 26 seconds before halftime.
Seven of Chicago's 13 rushing first downs came in the first half as the Vikings' defensive front failed to close running lanes from start to finish.
"He was a great back," Dantzler said of Montgomery. "He made some hard runs, and we didn't wrap up as well as we should've. Just have to be more disciplined in our run lanes, also. Like I said, we just have to learn from this game and continue to build from it."