The Tigers (10-7, 3-0), tied atop the Ivy League standings with Harvard, won their fifth straight game.
Princeton won it from beyond the 3-point arc and at the foul line. Bray was 3 of 3 on 3-pointers. Will Barrett (10 points) and Mack Darrow were each 2 for 3 from long range. The Tigers finished 8 for 11 on treys. Columbia (9-9, 1-3) was 4 of 13.
The score was tied 50-50 midway through the second half. But Hummer, who scored 16 points, was 12 of 14 from the free throw line - including 7 of 8 in the last 4:28. After Columbia cut it to 69-66, Hummer hit 3 of 4 foul shots in the last 0:08 to ice it.
Maodo Lo led Columbia with 16 points.