The victory was just the fourth for the Big Green (7-18, 3-8) in its last 54 visits to the Palestra.
Two free throws by Mitola broke a 61-61 tie with 1:02 remaining, and his three-point play at the 22-second mark gave Dartmouth a 66-61 lead.
The Big Green led 48-36 after a jumper by Boehm with 15:17 left, but the Quakers (7-20, 4-6) got back into the game with a 10-1 run that included two 3-pointers by Dau Jok. They eventually pulled ahead 57-55 on a jumper by Miles Cartwright with 4:48 to play.
Tony Hicks scored 23 points to pace Penn and Jok added 14 on 4-of-4 shooting, all from 3-point range, plus two free throws.
Mike Brey is looking at former Notre Dame players to fill two assistant jobs that have opened up with the departures of Martin Ingelsby and Anthony Solomon.
Purdue's 2016-17 prospects got a jolt Wednesday when forward Caleb Swanigan announced he will return for his sophomore season.
Clemson's Jaron Blossomgame says he is withdrawing from the NBA draft and returning to school for a final season.