Thursday afternoon at Mahopac High School, it was the Tuskers who came in as two-time defending champions - and undefeated at 18-0.
But it was Yorktown's Katie Cumerford who broke a 9-9 tie, drilling the game-winning goal with just 14 seconds remaining to give the Huskers a thrilling, 10-9 victory.
Comerford finished with four goals for Yorktown (13-5) and Julia Cook added two goals.
Livy Rosenzweig led Somers with four goals, and Gabby Rosenzweig added three goals and two assists.
Yorktown plays in a regional game next Wednesday at Dietz Stadium at 5 p.m.
Check out the video to see Daily Voice talk to Yorktown coach Ellen Mager, as well as Comerford and Cook.
Click here to follow Daily Voice Lewisboro and receive free news updates.