After Michigan beat Western Michigan 13-12 last weekend, there were a lot of raised eyes when looking at the spread entering Saturday. The Sooners crushed UTEP 51-0 last weekend, and on paper, Michigan didn't have much of a chance. But the spread showed the game was going to be close and the Wolverines came out and played a whole new game. Michigan was more physical and took down No. 11-ranked Oklahoma, 17-10, to move to 2-0.Not all was perfect, but Michigan got the major win and here are four takeaways.Major improvements from Bryce UnderwoodUSA TODAY Network via Reuters ConnectIf you just look at the box score, you're not going to be super impressed with Bryce Underwood's stats. He threw for 111 yards and ran for 87 yards, along with a TD. But if you watched the game, you'd be impressed with Underwood's improvements. He rarely forced passes, he took what the defense gave him, and he appeared to gain confidence with Jason Beck allowing him to use his legs. Underwood was likely never going to put up big stats against Oklahoma, but Michigan has to be happy with what it saw from him. With the rushing attack being irrelevant aside from Underwood, he played the QB position well and there is something to build on heading into Week 3. Defensive line was fantasticUSA TODAY Network via Reuters ConnectKyle Whittingham said during spring ball that the defensive line was the biggest strength for Michigan — that has held its value. One of our keys heading into the game was to clog the lanes and make John Mateer beat you with his arm. Michigan allowed 110 yards on the ground and the Wolverines were consistently in the backfield. John Henry Daley had his big game, recording one sack and three TFLs. Dom Nichols had an unfortunate facemask penalty in the third quarter, but he was coming off the edge hard once again. Both Trey Pierce and Enow Etta made plays up the middle. Michigan can hang its head on having a very good D-line. Penalties continue to rear their ugly headUSA TODAY Network via Reuters ConnectPenalties were a big issue last weekend against Western Michigan, having nine of them. And things didn't change this weekend in terms of seeing the Wolverines have more discipline. It's now back-to-back games Kyle Whittingham's team is making terrible plays after the whistle, which is something that we aren't use to seeing. The Wolverines ran into the punter twice on special teams, a few unsportsmanlike penalties, the most notable coming in the third quarter when Michigan had Oklahoma inside its own five-yard line, but Jyaire Hill hit a Sooners' WR late. You're not going to beat good teams every time when you have11 penalties for 90 yards and Klyle Whittingham has to get that corrected. O-line is still a work in progressIMAGN IMAGES via Reuters ConnectKyle Whittingham opted to replace Evan Link at LG in favor of starting Nate Efobi at LG and Brady Norton at RG. Last week, we saw those three players rotate but that wasn't the case against Oklahoma. Norton appeared to do a good enough job, but Efobi was penalized a few times and he didn't have a very good game against the Sooners' D-line. And while pass protection was good for the most part, it was another game in which the Wolverines' O-line struggled to create push in the run game. Jordan Marshall was largely ineffective for the second game in a row, and while Savion Hiter had a few plays, he couldn't get much going on the ground either. It was Bryce Underwood who led Michigan's rushing attack and the Wolverines need to figure out what's going on in a hurry. Sign up for the Michigan Wolverines on SI newsletter for more free coverageAdd us as a preferred source on GoogleFollow