EDS: Columbia 74, Lehigh 64.
Columbia (6-7) trailed 41-38 four minutes into the second half when Baumann's layup triggered a 10-0 run in which Nwachukwu scored five points to give the Lions a 49-41 lead with 11:46 remaining.
Lehigh (6-7) twice led by five points during the first half and by 34-31 at halftime as Bryan White scored 11 of his 23 points.
Columbia won for the second straight game and the third time in four starts while the Mountain Hawks lost their second in a row and dropped their fifth straight on the road.
After the Mountain Hawks closed within 56-54, Joe Bova scored his only points of the game on a 3-pointer and Baumann scored five more on a jumper and a 3 to open the Lions' lead to 64-54 with 1:33 left.
Matt Szalachowski scored 14 points for the Mountain Hawks.
Brett Loscalzo had 10 points for the Lions including six free throws in the game's final 1:07.