Williams scored 8 points in Troy's 12-3 sprint into halftime - forcing 13 first-half turnovers and building a 38-18 lead.
The wire-to-wire triumph puts Troy (10-18, 5-11 Sun Belt Conference) one game up with three to play on Texas State (which lost Saturday) in the scrap for the eighth and final tournament seed. Louisiana-Monroe (9-15, 6-10) is clinging to the seventh seed.
Williams hit 6 of 10 3-point shots (the Trojans were 9 of 25 on 3s overall) and Tevin Calhoun scored 15 points. Calhoun and Williams scored the last 18 points for Troy - Williams on back-to-back-to-back 3s.
Nick Coppola led the Warhawks with 10 points.