We started several weeks ago with 65 teams, and the field has been whittled down to two.
One one hand, there is Duke, led by the classy legend Mike Krzyzewski. Led by Oregon-born Kyle Singler, Duke is firing on all cylinders after routing West Virginia on Saturday.
Then there's Butler, the underdog that's for real. Gordon Heyward leads the charge for Brad Stevens' balanced team that's defeated Syracuse, Kansas State, and Michigan State.
Click here for the SBNation.com preview of tonight's game.
"We don't have to better than Duke 364 days out of the year" Butler head coach Brad Stevens told ESPN. "We don't have to be better than Duke for 23 hours on Monday. We just have to be better than Duke for 40 minutes"