Okonji was a prominent player for the Green Eagles (now the Super Eagles), having been first invited to the national team in 1963 and playing until 1973. During his decade with the national squad, he played alongside legendary figures such as Joseph Erico, Peter Anieke, Paul Hamilton, and Sebastian Brodricks.
His career included memorable performances in international friendlies against teams like Queens Park Rangers and Fortuna Düsseldorf. One of his defining moments was scoring the final goal at the historic Lagos City Stadium (now Mobolaji Johnson Arena, Onikan) on June 6, 1973, in a friendly match marking the stadium’s symbolic closure.
At the club level, Okonji represented top Nigerian clubs including the defunct Sharks, NEPA of Lagos, Port Authority of Lagos, and Aba Giant Killers (now Enyimba). After retiring as a player, he moved into coaching, managing several teams including NEPA FC Lagos, Guinness FC, and Delta Force.
