Chasidy Bouldin scored 12 of her team-high 19 points for Calhoun in the first half as the Lady Warhawks built as much as a 15-point advantage over the wounded Frederick Lady Cougars.
But with 51/2 minutes left until the break, FCC closed with a rush on the pinpoint shooting of Angie Levarto to close the half facing a 38-28 deficit.
"(Calhoun) hurt us inside more than we thought they would," said Frederick coach Jack Mehl. "We didn't take advantage of all our opportunities, and (Calhoun) did. With about 31/2 minutes left, we had a real opportunity to cut into their lead, but we missed some key foul shots."
While Bouldin was saddled with three fouls, Catrina Woods and Sonya Romine stepped up their offensive games in the second half, each finishing with 16 points. Bouldin grabbed 12 rebounds and Woods hauled down 12. Calhoun outrebounded Frederick, 44-32.
"Woods was able to penetrate the second half and open up some things inside," said Calhoun coach Amanda Marks. "And Romine hit some key shots from the baseline that helped us maintain momentum."
Frederick trailed by as many as 13 points with just over six minutes left in the game, but Levarto -who scored a game-high 31 points, including five three-pointers - took over offensively to pull the Cougars within striking distance.
But Calhoun nailed five of six free throws during the last 30 seconds to seal the win. Litisha Benson added 13 points for the Warhawks, who shot an impressive 49 percent from the field.
For Frederick, Judy Whims finished with 16 points. Allyson Merico contributed 10.
"We haven't won many games this year when it gets into the 70s. We like a much slower pace," said Mehl. "We came in kind of beat up today after a very physical game against Union County, but we got contributions from everybody. I'm very pleased with the way the girls rallied from their early-season start."