KANSAS CITY, Mo. — Tyler Dorsey’s teammates call him “Mr. March.” Yeah, that fits. Dorsey scored 20 points and made the go-ahead layup with 1:08 left, and third-seeded Oregon held on to end No. 7 Michigan’s dramatic postseason run with a 69-68 victory in a Midwest Regional semifinal on Thursday night. “We lean on him right now,” the Ducks’ Dylan Ennis said.