 Businessman Nikolaos Kanellakis stepped forward to provide the needed sum and become the club's new chairman.Kanellakis' arrival would be the beginning of the club's greatest erafrom the 1989 promotion, Ionikos would spend 16 of the next 18 seasons in the Greek top flight, up until 2007, and during that time the team would finish as high as 5th-place in the league (on two occasions), reach a Greek Cup Final, and compete in the UEFA Cup.Ionikos' UEFA Cup appearance came in the 1999–00 seasonthe opposition was French side Nantes, and Ionikos lost both home and away matches, 1–3 and 0–1, respectively.