Stanley Dimgba scored from the spot deep into injury time to give Enyimba the lead when Olalekan Gabriel felled Chinedu Udeagha inside the box.
It was an evenly contested affair but Enyimba scored early on from the spot after Gabriel Olalekan brought down Franco Atchou. Stanley Dimgba stepped up to convert from the spot.
Daniel Israel equalised for Rivers United off a Markson Ojobo cross. It was his first goal of the season.
More to follow