He lost his continental 400 m title to Innocent Egbunike at the 1985 African Championships in Athletics, although Tiacoh still managed to win a silver medal. The following year he improved his African 400 m record twice; first with a run of 44.32, then another of 44.30 seconds (which was the fastest by any athlete that season). He also managed to become the NCAA champion that year. Tiacoh ran at the 1987 World Championships in Athletics and easily progressed through the heats to the final. However, he only managed to finish in seventh place in the 400 m final as he could not match his previous form (his semi-final time of 44.69 s would have been enough to gain the bronze).
