Maurice Barrow chipped in 10 points and three steals for Fairfield, which had 12 steals. Needham finished with seven assists, more than Milwaukee (4) managed as a team.
The Stags (6-5) took a 23-21 lead into the break after a back-and-forth first half that featured six lead changes. Milwaukee (3-7) missed 8 of 10 shots and committed three turnovers over the first nine minutes of the second half as Fairfield opened up a 43-26 advantage and began pull away.
Kyle Kelm paced the Panthers with 13 points and 14 boards.
Justin Jenkins, who had nine points, went 0 for 8 in his first seven games this year, but has made eight of his last 12 field-goal attempts over the last three contests.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.