Navy's last win in the series came on Feb. 10, 2010.
Chuku's 3-pointer capped a 9-2 run and gave Lehigh its first lead of the second half at 50-49 lead. His jumper at 1:59 regained the lead for the Mountain Hawks and Schaefer's two free throws with 30 seconds left capped the scoring.
Navy's Brandon Venturini put the Midshipmen up by four points with 2:52 left, but would go scoreless the rest of the way.
In the first half, Navy went on a late 12-0 run for a 10-point lead.