Frederick (17-8, No. 3 Herald-Mail poll) made all its mistakes at once against the Colonels, who were the region's top seed after racing through the regular season undefeated until its last game.
Magruder (18-1) got all four of its runs in the fourth inning, getting four singles, two fielder's choices and both Frederick errors to win it.
The Cadets meanwhile, got six hits off of Hughes, but couldn't get any of them in succession. Frederick had leadoff doubles in the first and fourth but couldn't score either time.
"We just couldn't string anything together," Bono said. "I don't think we were nervous. Their pitcher just had good command and could turn it up a notch. That's what good pitchers do."
It's what Candy Warden did all season for the Cadets, but she didn't get enough help on Thursday. Still, the Cadets deepest run in the playoffs in three years had Bono and his players looking for more.
"They're already thinking next year," said Bono, whose team had just two seniors. "They knew they were young and it's the first time in our juniors' career that we've gotten this far.
"It was one bad inning and (Magruder) made the plays. They didn't hang their heads too much afterward."