The Pride (20-4) advanced to the Class AA championship game and will face either Gates Chili (23-0) or Cicero-North Syracuse (18-3), the defending state and Federation champion, at 8:45 p.m. Saturday.
Saniya Chong scored 22 of her game-high 27 points in the second half after hitting just two points in the first quarter when the Pride fell behind, 16-13. Chong added eight steals and six assists.
Ossining cut the early deficit to 26-25 at halftime and outscored Sachem, 41-32, the rest of the way.
Jalay Knowles had 11 rebounds and played strong defense for the Pride.
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