Gray hit 3 of 6 from 3-point range as the Big Red (6-9) drained 53.3 percent (8 of 15) of its attempts from deep.
The road win was Cornell’s third straight, its longest road winning streak since winning five straight at the end of the 2009-10 season. Prior to this streak, the Big Red was 5-29 on the road under coach Bill Courtney.
American took a 28-27 lead with 18:35 to play, but then a Shonn Miller 3-pointer sparked an 18-3 Cornell run.
Blake Jolivette led the Eagles (5-9) with 15 points.
American won the rebound battle 44-36 but shot just 34.4 percent (22 of 64), including 5 of 21 from 3-point range.
The Eagles have now lost five of their past six games.