Rohrer, who stole second after his hit, got caught in a rundown between third and home on DeBarge's single, but scored when a South player dropped the ball trying to tag Rohrer.
The Rebels (5-1, 3-0) answered with three runs in the bottom half. Derrick Hendershot and Brandon Knight drew walks and Todd Jacobson drove both in with a triple to the right-field corner. Jacobson later scored on a fielding error.
South used a hit batter, an error and two walks to score another run in the third inning, then sent 10 batters to the plate in a four-run fourth to make the score 8-2. Zeke Ricketts drove in two runs with a single and two more Warriors errors led to the other two runs.
Boonsboro rallied for three runs in the fifth, knocking Feigley out of the game with two outs. Adam Chambers drove in a run with a single and two more scored on the Rebels' second and last error of the game. Feigley allowed five runs - two earned - on six hits and three walks while striking out four.
"He's a slow starter," South coach Ralph Stottlemyer said. "His confidence builds as he goes along. We were hoping to get five innings out of him, but when we batted around (in the fourth) his arm got cold. It had to be tough for all the pitchers in this weather."
The Rebels scored two more runs in the bottom of the fifth with help from another Boonsboro error to make it 10-5.
South reliever Spencer Cromer earned the save, going 2 1/3 innings and allowing two hits and one run - coming in the sixth on Chambers' RBI single - while striking out four.
Hendershot, the Rebels' catcher, threw out Chambers trying to steal second base with a perfect throw to end the sixth inning with Kyle Kane at the plate. Kane led off the seventh with his third single of the day, but South turned a 4-6-3 double play to erase it, and Cromer ended the game with a strikeout.
"Our defense tightened up tonight," Stottlemyer said. "We made some key plays, and Boonsboro was hurt because they didn't."
Knight made a diving catch in deep center field to save a run and end the top of the second inning for the Rebels.