A review of four hot issues after the Minnesota Vikings' 23-20 win over the Chicago Bears:

Peterson wills his way past Bears: Adrian Peterson might not have all of his breakaway speed as he plays with a strained groin, but the performance he turned in on Sunday was the kind of tour de force he churned out so often in the second half of his MVP season a year ago. Peterson ran for 211 yards against a steady diet of eight- and nine-man fronts; he faced at least eight defenders in the box on 24 of his 35 carries, according to ESPN Stats and Information, and averaged more yards per carry with eight or more in the box (6.1) than he did against seven defenders or fewer (5.8).

QB decision looming: The Vikings will wait to see how Christian Ponder recovers from a concussion as they try to make a decision on their quarterback for Sunday's game in Baltimore, but Matt Cassel once again had the Vikings' offense running smoother than Ponder has at many points this year. Cassel threw for 243 yards, and handled extra pressure better than either Ponder or Josh Freeman has this season. He hit 11 of his 17 throws for 148 yards and a touchdown against five or more pass-rushers, according to ESPN Stats & Information. His completion percentage against such fronts (65.9 percent this season) is better than Ponder's (61.9 percent) or Freeman's (33.3 percent). Cassel could be competing with either Ponder and Freeman, or just Freeman, to play next week against the Ravens, but he did enough to possibly get another start.

Special teams confusion: The end of Sunday's game brought a number of odd special teams situations that seemed to confuse the Vikings. First, after Blair Walsh tied the game in regulation, the Vikings kicked deep to Devin Hester, who returned the ball 57 yards and might have scored if Walsh hadn't angled him out of bounds. Coach Leslie Frazier admitted after the game the Vikings shouldn't have kicked to Hester, adding they expected him to down the ball in the end zone like he had with Walsh's other deep picks. When the Bears tried a 67-yard field goal on the final play of regulation, the Vikings hurried Cordarrelle Patterson out to return the kick, barely getting him on the field in time. And then, after Rhett Ellison's face mask penalty wiped out Walsh's would-be game-winning field goal in overtime, the Vikings' field goal unit stayed on the field before the offense came back out to try to get Walsh closer than 54 yards on third down. Frazier said the Vikings wanted to get 4 more yards for Walsh, but Peterson lost three and Walsh missed from 57.

Ellison gets "elephant off my back:" Had the Vikings lost, Ellison likely would have worn much of the blame; he couldn't control what might have been a touchdown pass from Cassel with less than five minutes to play. He wound up tipping the ball toward the Bears' defense, where Khaseem Greene wound up intercepting it and running it back to midfield. Then, Ellison's face mask penalty negated Walsh's field goal, setting off a bizarre scene in which referees sorted things out amid postgame fireworks. Wide receiver Greg Jennings had to be pulled back from the tunnel up to the Vikings' locker room. Asked what he was thinking after the mistakes, Ellison replied, "That I really screwed the team over and that I made a big mistake." And when Walsh hit the game-winning field goal, Ellison said it was "like an elephant off my back. I don't know. It was just a miracle, I guess."