The Panthers scored twice in the first inning and plated the rest of their runs in the sixth, then senior Jake Dyer picked up his second save of the year by stranding the tying Tribe run at third base in the ninth.
GSU improved to 6-7 in the league with the key victory and 15-20 overall, dropping the Tribe to 23-14, 8-8.
Panthers starter Justin Malone struck out seven over five innings without yielding an earned run. The GSU offense did not strike out once over seven innings against CAA strikeouts leader Matt Davenport (5-3), who allowed seven runs, four earned. GSU reliever Tyler Claburn (3-0) picked up the victory.
"We reached a point in the game where we needed to respond and we did it," GSU head coach Greg Frady said of his squad, which trailed by three runs entering the bottom of the sixth. "Winning tonight was huge... we had to get this game."
The Panthers entered the night in seventh place in the league standings, one spot behind the Tribe. The top six teams qualify for the postseason CAA tournament in May.
Freshman Caden Bailey added two hits Friday night while seven different Panthers scored GSU's runs.
The Panthers strung together three singles in the first inning, taking a 1-0 lead on Kody Adams' RBI single that scored Bailey, then making it 2-0 on Kolowich's RBI groundout that scored Brandon Williams.
A two-out rally by the Tribe in the fourth inning allowed the visitors to push three unearned runs across with four two-out singles.
The Tribe then added another run in the fifth on a passed ball and one more sixth on an RBI single to claim a 5-2 lead.
GSU surged back with five runs in the sixth inning, aided by three hits and a pair of Tribe errors.
An RBI single from Kolowich began the scoring, then Adams came around on a throwing error. Scott Sarratt then doubled home Kolowich as GSU tied it, 5-5. Mark Hogan and Sarratt scored two plays later on a fielder's choice that was thrown away by the Tribe defense trying to turn a double play, allowing GSU to go ahead, 7-5.
A bases-loaded walk in the next inning brought the Tribe to within one at 7-6, but Dyer ended the one-out jam by inducing two ground balls, the second of which shortstop Caden Bailey charged on and fired across his body to end the inning and preserve the lead.
The Panthers put two aboard with one out in the eighth, but a strikeout and caught stealing ended the insurance opportunity.
With Dyer pitching his third inning in the ninth, William & Mary put the leadoff man aboard. He then reached third base after a pair of groundouts, but Dyer nailed down the save by inducing a third groundout to second base.
Dyer's 10th career save stemmed a four-game losing streak for GSU, who won its 13th game in 19 tries all-time against the Tribe.
The three-game series continues Saturday at 1 p.m. at the GSU Baseball Complex.