The game was called after five innings because of the 10-run mercy rule.
"It was the No. 1 priority for us this season to win a league championship," Bell-Jeff Coach Florencio Galindo said. "Before you can get to the playoffs you have to do well in your league, and it was always our goal to win league this season."
The Guards (19-5, 7-0 in league), who are ranked No. 2 in CIF Southern Section Division VII behind No. 1 Pomona Catholic, will find out who they will open up against in the playoffs when the pairings are released Monday.
Last season, Bell-Jeff advanced to the divisional championship game for the first time, losing to Pomona Catholic.
Against St. Anthony, the Guards received a fine effort by starting pitcher Amanda Maalouf. Maalouf went the distance, recording a two-hitter while striking out 10.
Monique Landini paced the offense with a two-run home run.
"Being league champions is something the girls can be proud of," Galindo said. "They have worked very hard for this."