Article at sportsline about the game's big matchup, notes that it shaped up as the blockbuster battle that everyone expected:
http://www.cbssports.com/nfl/draft/blog/rob-rang/21483627/clowney-vs-lew....
Suggests that Clowney gave Lewan problems, but that Michigan's All American lineman largely held his own. Lewan was not responsible for Clowney on the big play that nailed Vince Smith in the backfield and resulted in a fumble.
EDIT: After the game, according to the News, Lewan sought Clowney out. "I went up to him after the game and told him, 'You're one of the best defensive ends I've ever played against.' He said, 'You're the best tackle I've ever played against.' So that's a great compliment to have, but none of this matters because we didn't win the damn game."