Berekum Chelsea's title defence was dealt a severe blowà on Sundayà when they lost 1-0 at home to Medeama.
Louis Agyemang snatched what turned out to be the match winner in the 58th minute to shock the home fans.
The experienced striker received a pass from Sampson before placing it beyond goalkeeper Ernest Sowah.
Yusif Abubakar returned to his former employers where he was sacked as assistant coach in July and guided Medeama to humble a star-studded Chelsea side.
With striker Emmanuel Clottey dropped to the bench, Chelsea looked toothless to trouble the visitors although there were supplies from Gladson Awako, Eric Opoku and Abdul Basit.
Striker Sadat Karim wasted the best chance of the half on the half hour mark. He shot wide from an empty net after Medeama keeper Mozart Adjetey spilled an Abdul Basit half volley.
Medeama took charge of the game and scored the only goal of the game on 58 minutes.
Young midfielder Jacob Appau run solo from the Medeama half to locate Luis Agyemang.
The formerà Accraà Hearts of Oak influential striker fired a powerful shot from 35 yards to shock the home fans.