Sophomore Juliana Rodriguez led the attack with 21 points.
St. Joseph improves to 18-5 overall and 12-2 in the CHSAA, while Maria Regina drops to 11-6 overall.
Junior guard Madison Crocco led the offensive attack with a game-best 15 points while junior forward Elizabeth Bennett contributed 14 in the victory.
The Koalas, who won their fourth straight contest, improved to 13-3 overall and 7-1 in the Catholic High School Athletic Assocation (CHSAA).
St. Joseph Hill improved to 12-3, and have eight contests remaining in the regular season, with the last five at home.
The Koalas improve to 11-3 on the CHSAA season.
5-foot-9 senior shooting guard Amoni Byrd scored a game-high 24 points for the Stanners. Sophomore guard Juliana Rodriguez led the Koalas with 18 points on six three-pointers.
The Koalas are 9-2 heading into Monday's game versus Molloy