The former Harambee Stars captain struck in 33rd minute after Nicolas Fauvergue had opened accounts for the comfortable win.
Oliech was elated with his goal that arrived after a long drought, with his last strike for the side coming back in mid February, when AC Ajaccio beat Olympique Lyon 3-1.
“It feels nice to find the back of the net again. I know my last goal came back in February but it was good to remain composed and keep playing until I scored again. I am happy for my team because we won this derby in a convincing way,” Oliech told club’s official website.
The win leaves Ajaccio lying 13th in the 20 team log while GFCO are in position 12. Tours, Troyes and Orleans take up places one to three, all with six points.