The Sailors fell behind by 15 points in the first half and could not recover in a 65-54 loss.
Union grabbed a 24-11 lead after the first quarter. In the second half, the Sailors were able to whittle the lead down to six, but a late Union run led it to the victory.
Jordan Bledsoe finished with 22 points and six rebounds for Mona Shores. Jonathan Pittman and Paul Ritter added eight points each.