Tiatia made his debut for Wellington in 1992, playing through the advent of professionalism and then represented the Hurricanes in the Super 12 between 1996 and 2002.

match list He then moved to Japan to play four seasons for Toyota Verblitz before signing for the Welsh region the Ospreys.

He became a cult figure at the Ospreys impressing fans with his all action style and appetite for work around the field.

Tiatia was also involved with the Japanese national rugby team, under head coach Eddie Jones.

Tiatia was later also involved with coaching the Japanese national team ahead of their November 2013 Test match against the All Blacks, which New Zealand won 54–6.