Bailey Breen scored 33 points and top-seeded Oceanside (19-0) advanced to the Class B South girls’ basketball semifinals, shaking off ninth-seeded Biddeford (12-8) for a 67-46 victory at the Portland Expo.

The Mariners, taller and larger at every position, led just 26-18 at halftime but went on a 16-2 run in the first five minutes of the second half.

Oceanside will take on fourth-seeded Lake Region in the semifinals at 2:45 p.m. Tuesday at the Expo.

Breen, who averages 30 points, was dominant. She scored twice on rebounds and again on a 3-pointer to help Oceanside open a 9-0 lead. She had 15 points by halftime and added 11 in the third quarter.

Jordyn Crump hit five 3-pointers and led Biddeford with 19 points. Hannah Smith finished with 18.