 Pari gbolohun ti o tẹle: OSullivan ti jẹ ọmọ-ọmọ snooker lati igba ewe, o ṣe aṣeyọri ọgọrun ọdun akọkọ rẹ ni ọdun 10, o gba idije British Under-16 Championship ni ọdun 13, o ṣaṣeyọri aṣeyọri idije akọkọ rẹ ni ọdun 15, o si gba IBSF World Under-21 Snooker Championship ṣaaju ki o to di ọjọgbọn ni ọdun 1992, ni ọdun 16. Ó gba oyè àkọkọ rẹ nínú ìdíje : 1993 UK Championship ni ọjọ ori ọdun 17 ati ọjọ 358, ti o jẹ ki o jẹ oṣere ti o kere julọ lati ṣẹgun iṣẹlẹ ipo ọjọgbọn, igbasilẹ ti o tun ni. O tun jẹ oṣere ti o kere julọ lati ṣẹgun Masters, eyiti o kọkọ ṣe ni ọdun 1995, ti o jẹ ọdun 19 ati ọjọ 69. 