Plomb and Wilson made four 3-pointers apiece. Army (9-3), which gets 40 percent of its points on treys, rebounded from a 7-of-37 3-point night in a loss to Marist that snapped a five-game win streak. The Black Knights were 11 of 28 from the arc, the 10th time in 12 games they have reached 10 3-pointers.
Kennedy Edwards gave Army the lead for good with a 3-point play with 15 minutes left. Monmouth closed to 87-84 with a minute to go. Plomb hit a jumper then two free throws to seal the victory.
Monmouth (9-4), which received a program-best 11 points in The Associated Press poll released Monday, had its five-game winning streak snapped. Justin Robinson led the Hawks with 23 points.
Army opens Patriot League play Wednesday at Lehigh.