 Both titles were relinquished when McKenzie won the IBF flyweight Title on 5 October 1988 with an 11th-round knockout over Rolando Bohol.After two title defences and one non-title, McKenzie lost the IBF flyweight title to Dave McAuley on 7 June 1989 in his first defeat.An unsuccessful challenge for the European (EBU) Bantamweight title on 30 September 1990 saw McKenzie lose to Thierry Jacob of France.