NEW YORK -- Phil Greene IV scored a game-high 22 points to help St John's hold off Monmouth 64-54 Friday night.
The Red Storm (3-1) did manage to build a 34-28 lead early in the second half after a three-ball by Harrison.
Monmouth (1-3) countered as they mounted a 12-4 spurt to take a 40-38 lead.
St. John's responded with a run that gave it a 50-41 lead with 7:05 to play after a jumper by JaKarr Sampson.
On a night where St. John's looked ripe for an upset, they needed a pair of 3-pointers from Harrison in the final 4:07 and another triple from Greene, the latter coming with just 1:04 to play.
Chris Obekpa finished with nine blocks as St John's had 15 total, tying a school record.