The Gabonese had fallen behind to Youssef El-Arabi's first-half penalty but, just after the hour mark, Evouna worked his way past several Moroccan defenders and produced a calm finish to earn a draw for his side.
Both sides had interim coaches at the helm and after a cagey opening, Morocco captain Adel Taarabt fired a warning shot, sending a curling effort over the crossbar from 25 yards in the 16th minute.
With half-time approaching, Gabon went close to an equaliser, Frederic Bulot's deflected free-kick wrongfooting Youssefi, who was lucky to see the ball fly just over the crossbar.
Evouna's superb finish rendered that miss irrelevant five minutes later though, the striker picking up a loose ball before beating three men inside the area and slotting a cool finish beyond Youssefi.
Taarabt almost won it for his side 12 minutes from time, but his low free-kick was tipped onto the post by Didier Ovono and bounced away to safety.
