Georgia Southern (9-9, 2-1 Southern Conference) shot 50 percent overall, including 11 of 21 from beyond the arc. Jelani Hewitt added 21 points as well, and Matias pulled down 10 rebounds.
Furman (6-12, 0-5) was led by Stephen Croome with 26 points.
Furman led the entire first half and was up by as much as 10 before the intermission, but Georgia Southern trimmed the lead to 3 at the half as Bussey drilled a 3-pointer with 8 seconds remaining.
The Eagles trailed by four late in the second half, but Matias hit one of two from the line, then Hewitt drained a trey with 21 seconds left to force overtime.
Georgia Southern scored first in overtime and never relinquished the lead.
Mike Brey is looking at former Notre Dame players to fill two assistant jobs that have opened up with the departures of Martin Ingelsby and Anthony Solomon.
Purdue's 2016-17 prospects got a jolt Wednesday when forward Caleb Swanigan announced he will return for his sophomore season.
Clemson's Jaron Blossomgame says he is withdrawing from the NBA draft and returning to school for a final season.