The Eagles have won three straight following a three-game losing streak in Big South Conference play. After starting the season 3-1, the Flames (5-15, 2-5) have won just two of 14 since.
Liberty scored the first five points of the game but Winthrop took over from there, putting together an 11-0 run and built a 31-22 lead at the break.
Bjorn Broman's 3-pointer for the Eagles extended the lead to double figures (40-28), and a Gavin layup pushed it to a game-high 19 (71-52) with 1:45 to play.
John Dawson led Liberty with 15 points.