He threw himself to his right to parry Caleb Ekuban's spot-kick. It was the only failure of the shoot-out.
Minutes before Mustapha’s entry, the starting goalkeeper, Mouez Hassen, was left helpless as Rami Bedoui headed past him into his own goal to draw Ghana level.
The blunder came during relentless pressure from Kwesi Appiah’s men to cancel out Taha Yassine Khenissi’s 73rd minute opener for Tunisia.
That his strike was deemed the first goal of the encounter will be long debated in Ghana. André Ayew thought he had given his side the lead just before half-time when he thrashed home past Hassen. But the referee, Victor Gomes, ruled out the goal for handball.
In the absence of the video assistant referee – Var - Ghana were unable to challenge the decision. The technology will only be available from the quarter-finals which start on 10 July.
Tunisia, who have yet to outscore their opponents, will take on tournament debutants Madagascar on 11 July at the Al Salaam Stadium in Cairo.