The Lady Mariners will face A-qualifier Harborfields Wednesday in the Suffolk County Small Schools Championship.
The winner will advance for a shot at the Section XI title against the large school champion, which will either be North Babylon or Sachem East, depending on the outcome of a Tuesday game at Ward Melville.
The Southampton girls basketball team defeated Center Moriches for the Section XI Class B title, then beat C-qualifier Stony Brook in the B-C playoff.
The Small Schools Championship begins at 7 p.m. Wednesday at Northport High School. Admission is $6.
Regardless of the outcome of Wednesday's game, the Lady Mariners will compete at 7:30 p.m. March 6 at Hofstra University in the Class B Regional Semifinals versus the Section VIII Class B champs. Admission is $7.