Nyorai mberi kweiyi ndima - Diniz akaramba ari paArrows muna 1998, achibatsirana naMika Salo. Diniz akatsungirira kutanga kunopisa: mota yake yakatambura nematambudziko ebhokisi rekutenderera mumakwikwi matatu ekutanga uye yakatsungirira kukundikana kweinjini mumakwikwi eSan Marino neSpain. Akawana poindi yake yokutanga mumwaka uyu paakapedza ari pachinhanho chechitanhatu muMonaco uye akakwanisa kupedza mujaho muCanada neFrance. Diniz akatambura mamwe matatu akatevedzana ekudzoka, uye akapedza mijaho muHungary neBelgium
, mune yechigumi neimwe uye yechishanu zvichiteerana. Diniz akapedza mwaka nekurega mumakwikwi matatu ekupedzisira. Akapedza ari 14 muDrivers' Championship, uye akaenzana pamapoinzi newaaitamba naye Salo.