Stony Brook (22-10), which will play at top-seeded Albany (23-8) for the title next Saturday, has won eight straight games since losing to Vermont (18-12) on Feb. 7.
Both teams had double-digit leads as Vermont lead by as many as 16 and Stony Brook 11.
Carson Puriefoy made 1 of 2 free throws on back-to-back trips to the line, the last giving Stony Brook a 79-75 lead with nine seconds left. Trae Bell-Haynes answered with a layup and Vermont tied-up the inbounds pass with the possession arrow favoring the Catamounts.
With no timeouts remaining, Vermont found an open Ethan O'Day but his jumper fell short.