Freshman Elizabeth Durrant scored the only goal of the game in 54th minute on a beautiful strike into the corner of the net.
"It feels really great to do it as a freshman," Durrant said. "To be the one of the ones that you thought wouldn't normally play, and then to get the goal is amazing."
Senior goalkeeper Liz Empey notched her 10th shutout as Dixie survived two last minute shots by Juan Diego that hit the crossbar.
"It's the best feeling," Empey said. "As soon as that buzzer went off, it's my senior year and there is no better way to end it."
The championship is Dixie's first since 2006.
In the 2A title game, Summit Academy beat Waterford, 2-1, on goals by Ali Gorringe and Juliana Stratford.