[5][6] After playing lower grades with the South Sydney Rabbitohs in 2011 and Parramatta Eels in 2012,[7] Fonua-Blake joined the St. George Illawarra Dragons in 2013.

[12] On 19 January 2015, he was stood down by the club due to disciplinary reasons, before having his contract terminated on 30 June 2015 when he pleaded guilty to assaulting his girlfriend.

[13][14] At the end of 2015, he was granted approval by the NRL to train with the Manly Warringah Sea Eagles from 1 November of the same year.

[16][17] On 7 September, following the end to Manly's season (having finished 13th), Fonua-Blake was named in the New Zealand Kiwis train-on squad for the 2016 Four Nations tournament.

Fonua-Blake played in Manly's elimination final defeat against South Sydney at ANZ Stadium the following week which ended their season.

[22][23][24] In round 8 of the 2020 NRL season, Fonua-Blake was sent off after full-time in the match against Newcastle after he called referee Grant Atkins a "fucking retard", and later a "spasticc".

Fonua-Blake said this in response to Manly being denied a penalty try in the final moments of the match, which resulted in a 14-12 loss to the Newcastle Knights at Brookvale Oval.

[31] Fonua-Blake played 26 games for the New Zealand Warriors in the 2023 NRL season as the club finished 4th on the table and qualified for the finals.

[37] *denotes season competing In 2015 he pleaded guilty to assault charges after pushing and kicking his partner after a night out drinking.