Kwasi Acheampong scored the match winner to deny Medeama a share of the spoils at the Golden City Park where Berekum Arsenals won 3-2 on Wednesday.
The game looked to be heading for a draw after Louis Agyemang's brace had cancelled out Prince Amponsah and Jafaru Danjuma's goals for Arsenals.
But in the 72nd minute, Acheampong was credited with goal from a goalmouth melee.
The win was Arsenals second this season after five defeats.
