After school, Nanai Williams started playing for
Counties Manukau and re-signed with for the 2010 season. In the same year, Nanai-Williams signed for the
Chiefs and made his
Super Rugby debut for the
Hamilton-based franchise, against the
Sharks. He stayed in the franchise until 2015, and was a key fixture in the Chiefs' Super Rugby triumphs of 2012 and 2013, proving himself an invaluable utility option as he covered wing, outside centre and full-back. After the 2015 Super Rugby season, he signed for the japanese
Top League side
Ricoh Black Rams. In October 2016, it was announced that he would re-sign for the Chiefs in time for the 2017 Super Rugby Season and with Counties Manukau. In December 2017, after 85 Super Rugby appearances, he signed a three-year contract with French powerhouse
Clermont Auvergne, then reigning
Top 14 champions, until the end of 2021. == International career ==