The Cougars end the season with a 38-22 record and the program's fifth NCAA appearance with the fourth SoCon Regular Season championship.
Renfro and Cruz were locked in a defensive struggle until a fluke play in the sixth inning allowed the Yellow Jackets to get on the board. Designated hitter Zane Evans lifted a high fly ball to left center field that CofC's Marty Gantt lost in the sun. The ball fell and Brandon Thomas came around to score and give Tech a 1-0 lead.
That was the only scoring of the game until the ninth inning when Connor Lynch lifted a two-run homer to the left field corner off of Kyle Owings to put the game out of reach.
Cruz (8-3) and Zane Evans held College of Charleston to just three hits in the entire game, as Cruz struck out three in six innings of work.
Renfro (6-8) pitched 7.1 innings, scattering six hits and allowing just one run while striking out five Yellow Jackets.
"This was a tough one. We pitched really well and played well defensively," head coach Monte Lee said. "Josh Renfro was outstanding and battled the entire game. We just couldn't find a way to score runs. Their pitching staff did a great job of getting ahead in the count and putting the ball down in the zone. Overall, I'm so proud of our seniors and the way that this team competed this season."
Rob Harding, Brandon Murray and Jimmy Holton picked up the only hits for the Cougars. Harding continued his stellar defensive play during the Regional, leaping to snag one potential double and charging a bunt attempt and throwing out a GT batter off-balance.
With the win, Georgia Tech advances to face regional host Florida in the Regional Championship game on Sunday night.
The Cougars move their record to 9-10 in five NCAA Regional appearances since 2004. College of Charleston has won at least one game in every Regional.
College of Charleston's Matt Pegler, Daniel Aldrich and Cody Martin were all named to the Gainesville All-Regional team.