ANN ARBOR >> Jehu Chesson returned the opening kickoff 96 yards for a touchdown and No. 18 Michigan scored on offense and defense to build a four-touchdown lead by halftime in a 38-0 victory over No. 13 Northwestern on Saturday.The Wolverines (5-1, 2-0 Big Ten) have won five straight since their opening loss at Utah under coach Jim Harbaugh, building momentum going into a showdown at home next week against No.