Defense dominated the day as Wisconsin shot just 34.8% from the field while the Phoenix made only 35.1% of their shots.
Jordan Fouse added 13 points and eight rebounds for the Phoenix (7-2).
A pinpoint passer with wide-receiver speed, Mariota came into his junior season as the favorite to win the 80th Heisman.
Along with the 17 points, Dekker grabbed five rebounds, had three assists and two blocks for Wisconsin (10-1).
Green Bay is coming off a road win at South Dakota State.
The Phoenix is coming off a big win at Miami.
Reports say Pitt coach Paul Chryst will become Wisconsin’s next head coach.
The junior becomes the third Badgers player to win the award.
Alvarez also was pressed back into service to coach the Badgers in the 2013 Rose Bowl after Bret Bielema left for Arkansas.
Wisconsin has beaten Green Bay, Maquette and Milwaukee this year