The Tigers (11-2), who also got 12 points from Hans Brase, are off to their best 13-game start since the 1997-98 season.
The Tigers led by seven at halftime but the Flames (6-9) came back to take the lead at 47-46 with 15:10 left. The lead changed hands six times in the second half until the Tigers finished the final 2:31 on a 14-7 run.
Princeton turned 10 Flames turnovers into 18 points.
Liberty's leading scorer at 13.9 points per game, Antwan Burrus, missed the game because of a back injury. His playing status is day-to-day.