A first-half strike from Razak Yussif was enough to secure all three points for the Dade Boys at the Accra Sports Stadium.
The 37-year-old was named on the bench as Samuel Boadu opted for a midfield trio of Ushau, Gladon Awako and Amankwah Baafi.
However, Olympics proved superior in the middle of the park and a swift counterattack saw Annor Walker’s side take the lead after 30 minutes. Razak Yussif was allowed the time and space to run through on goal before calmly slotting the ball past Richmond Ayi. Despite Hearts’ renewed efforts in the second half, the Phobians couldn’t find the equalizer as they were condemned to a second defeat in their last three league matches.
Meanwhile, Boadu’s side has now dropped to seventh on the league table, 10 points behind rivals Asante Kotoko who have two games in hand.