Malian striker Malick Toure led Setif’s attack, which also featured Ahmed Kendouchi and Houssam Eddine Ghacha.
Kotoko started bravely as Christopher Nettey drove a shot which deflected off teammate Emmanuel Gyamfi into the hands of goalkeeper Sofiane Khedairia, Emmanuel Sarkordie fired a shot from outside the box over the bar and Keita hit the roof of the net with a header.
In the 27th minute, Toure made a scoring attempt for Setif but his effort, after being located by Merbah Messala’s in-swinger, went wide.
After Opoku saw a penalty shout ignored by the referee, the striker went knocking again shortly after but goalkeeper Khedairia reacted sharply to tip out the effort for a corner in the 32nd minute.