Marcus Landry added 11 points for the Badgers (8-2), who established control midway through the first half with a 17-0 run.
The Phoenix (6-4) had made five consecutive field goals in the midst of a 12-0 run to take a 15-7 lead.
But the Badgers came right back and the Phoenix went cold, missing 12 consecutive field goal tries.
Michael Flowers and Kevin Gullikson converted three-point plays and Brian Butch sank a 3-pointer, giving Wisconsin a lead it would never relinquish.
Free throws by Butch and Trevon Hughes put the finishing touches on a 30-5 Wisconsin run, and the Badgers had a 37-24 lead at halftime.
The Phoenix never cut the lead to less than nine points after the break.
Cordero Barkley scored 11 points to lead the Phoenix. Mike Schachtner, Green Bay's leading scorer who was averaging 20.2 points per game, scored just eight points on 2-of-13 shooting.