The win clinches the Colonial Athletic Association series for the Panthers, who are now 4-1 in the league and 11-13 overall. JMU, the CAA preseason favorite, fell to 0-8 in league action and 5-17-1 on the year.
The Dukes had the tying run on second base in the top of the ninth, but pitcher Jake Dyer snagged a lined shot back up the middle to end the game and pick up his ninth career save.
Starter Ben Marshall (2-2) earned the win by holding the Dukes to one run over six innings, striking out four. Sophomore reliever Aidan McLaughlin threw two scoreless innings to preserve the Panther lead in the seventh and eighth.
Williams went 3-for-3 on the day with two RBIs and a run scored while Wood's two-run single in the eighth padded the GSU lead.
"Those two guys have had a wonderful two games and that's really what you expect from your seniors," GSU head coach Greg Frady said of the duo, which also teamed up to deliver a walk-off win the night before. "All day long we were grinding it out, making plays and we found a way to win the game. This is a great victory."
The Panthers plated a run in the first inning when Mark Hogan ripped a two-out double, his fourth of the season, then scored on Williams' first single of the day.
Williams then doubled home Drew Shields from first with two outs in the third to make it 2-0, GSU.
The Dukes cut the lead in half in the fifth on a sacrifice fly but Marshall ended the threat by inducing a foul out with runners on the corners.
Again in the seventh, the Dukes put runners on the corners with two outs, but this time McLaughlin ended the rally with a groundout to hold a 2-1 lead.
The Panther offense then added to its lead in the bottom of the eighth. After loading the bases, Wood ripped a single into left field that scored Williams and Hogan for a 4-1 advantage.
The Dukes scored once in the top of the ninth against Dyer, then put runners on second and third base with two outs. Dyer then snagged a lined shot up the middle off the bat of Chad Carroll that would have likely tied the game for the final out as JMU stranded 14 total baserunners in the loss.
Dyer, who was named to the NCBWA Stopper of the Year Watch List, picked up his first save of the year after pitching in a starter's role through the first part of the season.
The Panthers have now won four of their last five meetings with the Dukes dating back to last season and are 4-1 in CAA play for the second straight season.
The three-game series wraps up Sunday at 1 p.m. at the GSU Baseball Complex, when the Panthers honor members of the Wounded Warriors Project with a special first-pitch ceremony.