Seaford will be the fifth seed in the state tournament, and Smyrna is the 6th seed.
Smyrna will face Seaford for the Henlopen Conference championship at 4 p.m. Saturday at Dover High School.
The Riders trailed by only three points early in the second quarter, then Smyrna ratcheted up the defense.
Ja’Bree Pitts led the Cavaliers with 12 points and was the only player in the game to score in double figures.
The game had a little bit of everything including displays of good sportsmanship after a few strong fouls by each team.