Prempeh beat T.I. Ahmadiyya Senior High School 25-18 in the Boys Division while Kumasi Girls topped Kumasi Wesley Girls High School 12-7 in the Female Division.
The regional competition is taking place at the Our Lady of Grace Senior High School in Mampongteng for the first time.
Qualifying to the semifinals puts Prempeh and Kumasi Girls just a step away from securing one of two regional spots at the national games in Accra.
Kumasi Girls got on the board late in the game with Center Abigail Agyapongmaa scoring a couple of baskets to separate themselves from the pesky opponent.
Prempeh battled its demons from the free throw line several times in its animated game against T.I. Ahmadiyya to qualify to the final four.
Kumasi Girls are the defending regional and national champions and Prempeh is in the hunt for a long awaited regional title.
By Yaw Adjei-Mintah
@YawMintYM on Twitter