He joined Manly's squads in 2009 at the age of 16 and played the entire year in the Sea Eagles Toyota Cup. He primarily played at but also played on the wing and in the centres. Despite a season-ending injury to Manly 1st-grade fullback Brett Stewart in Round 1 of the 2010 NRL season, Hopoate had to wait until Round 13 to make his debut as coach Des Hasler preferred to use Ben Farrar in the custodian role. Hopoate is the son of former Manly player John Hopoate, though other than his physical size, speed, strength and general play, he has shown none of the "bad boy" habits which saw his father often on the sidelines through suspension. Hopoate also represented the Australian Schoolboys team. In Round 3 of the 2011 NRL season, Hopoate scored his first ever double against the Newcastle Knights at Brookvale Oval. Hopoate was part of the Manly side that defeated the New Zealand Warriors in the 2011 NRL Grand Final where he was denied the opening try but did produce a flick pass that sent Glenn Stewartover the line for a crucial try in the second half.
Parramatta Eels
In October 2011, Hopoate signed a 2-year contract with the Parramatta Eels starting in 2014, after his Mormon mission ended. In April 2015, he agreed to re-sign with the Eels on a 3-year contract, however due to legal complications, the contract wasn't registered and Hopoate was left a free agent. In 2016, Hopoate took The Parramatta Eels to court and was seeking $1.83 million in damages. On 29 October 2016, both parties came to an agreement of a $400,000 settlement.
Canterbury-Bankstown Bulldogs
On 7 December 2015, Hopoate signed a 2-year contract with the Canterbury-Bankstown Bulldogs starting in 2016. In his first season with Canterbury, Hopoate announced that he would not be playing for the club on Sundays due to his religious faith. Hopoate even went as far to say that he would not play for Canterbury in the grand final if the club was to make it that far as the final is on a Sunday. Hopoate missed Canterbury's qualifying final against Penrith due the game being played on Sunday. On 14 May 2017, Hopoate reversed his decision and declared that he would be playing Sunday games again for Canterbury. On 1 June 2017, Hopoate re-signed with the Canterbury-Bankstown Bulldogs for a further three years until 2020. On 27 November 2019, Hopoate signed a two-year contract extension to remain at Canterbury until the end of the 2021 season.
Representative career
NSW
On 5 June 2011 Hopoate was selected to play State of Origin for New South Wales in Game 2 against Queensland at ANZ Stadium. He is the second youngest player behind Brad Fittler ever selected to play for NSW and he scored a try on debut helping NSW level the 3 game series at one all with an 18-8 win.
Tonga
In 2017 Hopoate elected to represent the nation of his ancestral heritage, Tonga. He played fullback in every game of their stunning charge to the 2017 Rugby League World Cup semi-finals. He was a tryscorer in their shock win over New Zealand in the pool stage of the tournament. He was named at fullback again for the historic first-ever Test match between Tonga and the Australian Kangaroos on 20 October 2018, played in front of a sold-out crowd at Mount Smart Stadium, Auckland.
