Monmouth, overcoming an 11-point second half deficit, took the lead for good when Robinson hit a 3-pointer for a 56-55 edge. Robinson then forced a turnover and Siena intentionally fouled Deon Jones, who made a pair of free throws to make it 58-55.
With fouls to give, Monmouth intentionally fouled Siena twice. On the Saints' second inbounds pass, Max DiLeo stole it and tipped it to Robinson, who fed Jones for an alley-oop, one-handed dunk, stretching the Hawks lead to 60-55 with 22 seconds left.
Jones had 22 points and 13 rebounds for Monmouth, which outrebounded Siena 47-29.
Ryan Oliver scored 18 points to lead Siena.