Tillotson made one of two free throws with 10 seconds left before Walker's game-tying basket. Sean O'Brien's basket tied it for the Raiders (13-14, 9-7) at 79 with 31 seconds left in regulation to send it into overtime.
Shatori Walker-Kimbrough scored 22 points and Brionna Jones (Aberdeen) added 14 points and 11 rebounds.
James Madison 61, Towson 45: Jazmon Gwathmey scored 21 points and the host Dukes (20-5, 13-2 Colonial Athletic Association) defeated the Tigers.
James Madison held Towson (6-20, 3-12) to 27.4 percent (17-for-62) shooting from the field and kept Towson under double digits in each of the first three quarters for a 41-23 lead entering the fourth quarter.
Dominque Johnson had 13 points and seven rebounds and Raven Bankston added 11 points for the Tigers, who lost their second straight game.