Sulley Muntari made his debut for Hearts of Oak as the club lost to rivals Great Olympics in the Ghana Premier League on Sunday.
A first-half strike from Razak Yussif was enough to secure all three points for the Dade Boys at the Accra Sports Stadium.
Muntari joined the Phobians earlier in the week following days of speculation and was immediately included in the squad to face Olympics.
The 37-year-old was named on the bench as Samuel Boadu opted for a midfield trio of Ushau, Gladon Awako and Amamkwah 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 equliser 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.