Liberty Professionals halted Asante Kotoko's title charge after defeating the champions 1-0 on Sunday to cut their lead in the First Capital Premier League.
A second half goal by Mohammed Cissey helped the Dansoman side to the famous win.
The victory will boost Liberty's struggles down the table as they still have a game in hand with the competition left with nine matches to go.
Cissey scored in the 52nd minute after a goalless first half at the Carl Riendorf Park.
The result leaves a nervy Kotoko with an 11-point cushion at the top as they prepare for their next game against top-four contenders, Heart of Lions.