Brewer was fouled on a drive for Kent State (10-5, 1-1 Mid-American) with the game tied at 65. Anthony Johnson missed a runner for Northern Illinois (7-6, 1-1) in the final seconds.
After shooting 0 for 3 in the first half, Manley made all five of his 3-point attempts in the second. He converted a four-point play on his fifth 3-pointer to pull Kent State even at 58-all.
Jimmy Hall added 15 points and Brewer finished with 11 for the Golden Flashes.
Threloff scored 21 and Johnson added 14 for the Huskies.