 Nyorai kupfuurira kweiyi ndima - Pakati pa1996 na1999, OSullivan akasvika kumatatu enyika semi-fainari mumakore mana. Mumakwikwi eNyika a1997, akawana mukana wake wekutanga mumakwikwi ehunyanzvi; yakaunganidzwa munguva yemaminitsi mashanu nemasekondi masere, inoramba iri yekumhanyisa kukwikwidza kwakanyanya munhoroondo yesnooker. Akakunda zita rake rechipiri reUK gare gare gore iroro pa1997 UK Championship. Pasinei nokubudirira uku, basa rake rakakanganiswa nekukakavadzana muma1990. Munguva ye1996 World Championship, akarova mutevedzeri wemukuru wezvemashoko, izvo zvaakagamuchira kurambidzwa kwemakore maviri uye faindi ye 20,000. Pashure pokukunda Irish Masters ya1998, akabviswa zita rake nemari yemubairo apo kuedzwa kwemishonga kwakatevera mutambo kwakawana uchapupu hwecannabis mumuviri wake. OSullivan akazobvuma kushandisa zvinodhaka uye doro kakawanda mumakore ekutanga ebasa rake, izvo zvakaguma nemashiripiti muPriory Hospital yekugadzirisa. 