[3] After defeating Andy Ruiz for the vacant WBO title, Parker became the first heavyweight boxer from either New Zealand or the Pacific Islands to win a major world championship.

[20] He was the sole representative of his country in the quarterfinals after he beat Turkey's Yusuf Açik to face the Pan-American champion Yuniel Castro Chavez from Cuba.

[31] At the 50th Belgrade annual boxing tournament, Parker ended his amateur career defeating 2012 London Olympics berth winner, Johan Linde of Australia, to claim his third gold.

A Hamilton physical education school teacher and former Waikato Rugby league representative, Garmonsway had only three professional boxing bouts, amounting to two wins and one loss.

Parker secured the New Zealand National Boxing Federation title with a win marred only by a serious cut he suffered in the opening round when the fighters clashed heads.

[43] Parker continued his winning form after he knocked out WBO Latino heavyweight champion Irineu Beato Costa Junior in December 2014,[44] before doing the same to Jason Pettaway in March 2015.

Following a three-week camp as sparring partner to Wladimir Klitschko in Florida, Parker announced to fight three more bouts in 2015, re-commencing in Palmerston North on 13 June where he defeated Yakup Saglam via second-round knockout.

[47] Following the withdrawal of Japanese heavyweight champion Kyotaro Fujimoto, Parker beat replacement Bowie Tupou on 1 August in Invercargill, New Zealand, by first-round knockout.

The New Zealand-born Australian Meehan earned his shot at the promising heavyweight after winning the Super 8 competition and beating New Zealand veteran Shane Cameron.

[48] Parker's next two opponents were both named on 9 November 2015, with 24-year-old Daniel Martz selected for 5 December 2015 in Hamilton, followed by southpaw Jason Bergman on 23 January 2016 in Apia, Samoa.

The challenger offered very little on offense but displayed some impressive mettle in soldiering through a number of Parker onslaughts, the champion tenderising the body relentlessly in what proved to be the ideal workout against his first southpaw opponent.

[52] The fight took place with Parker winning a unanimous decision after twelve rounds, in front of a vocal home crowd at South Auckland's Vodafone Events Centre in New Zealand.

It was hyped as a Trans-Tasman grudge match with Parker's IBF world heavyweight mandatory position on the line which attracted the attention of the Australian media and public.

[59] The belt was vacated by Tyson Fury, who was battling depression and drug issues and had not fought since November 2015 after defeating Wladimir Klitschko for the WBA, IBF, and WBO titles.

[60] Although the WBO president Francisco Varcarcel said his preference was to set up a four-man box-off for the vacant title involving the four leading available contenders for their belt but it had gone down the route of their own rules book which gave number one ranked Parker the first rights to challenge.

[62] With his sudden announcement that he would relinquish his various heavyweight world title belts due to his issues with various problems, it was unclear exactly how the WBO and WBA would go about filling the vacancies.

But before Fury vacated, Duco Events promoter Dean Lonergan announced in early October he had been negotiating an alternative WBO title fight against Andy Ruiz, suggesting he had a chance of reaching a deal with Bob Arum.

[65][66][67] In December 2016, David Haye was made mandatory challenger for Parker's world title, however, he chose to fight cruiserweight Tony Bellew in a heavyweight grudge match on pay-per-view.

It saw WBO President Francisco Varcarcel take to social media to give Fury until 25 February to finalise the bout, otherwise, he would lose his position to challenge Parker for the world championship.

[97][98] It was later reported that Parker's team were looking at Browne as a potential match-up if they failed to land a unification fight with WBA, IBF and IBO heavyweight champion Anthony Joshua (20–0, 20 KOs).

[121] A few weeks later, co-promoter Bob Arum was negotiating a deal for Parker to fight in Atlantic City, New Jersey on 18 August against Top Rank promoted Bryant Jennings (23–2, 13 KOs).

[123][124] On the morning of 7 June, it was confirmed that Parker would instead return to the UK for a third-straight fight on 28 July at The O2 Arena in London against Dillian Whyte (23–1, 17 KOs) on Sky Box Office.

Parker had an explosive start to round 12, knowing he needed a knockout to win, eventually knocked down a fatigued Whyte with 20 seconds left in the fight with a right hand to the head.

In their fourth contest, Fa and Parker fought in a do-or-die opportunity to secure a place at the 2012 Summer Olympics during the Oceania Boxing Championships in Canberra, Australia.

[163] In August 2020, Fa's manager, Mark Keddell, said the fight was close to being agreed, stating, "We've sent our final offer to them today and in terms of the money I just cannot see it being a problem.

[178] The day before the fight, the event looked to be in jeopardy as Chisora threatened to pull out, after losing a coin toss that meant he would have to walk to the ring first, which he objected to.

"[191][192] On 3 August 2022, it was reported the fight was set and an official press conference would take place later in the week to formally announce Joe Joyce (14-0, 13 KOs) vs. Parker in a 12-round heavyweight contest on BT Sport Box Office in the UK.

[214] Unwilling to let the third loss of his professional boxing career get in the way of re-gaining heavyweight world-championship status, Parker's next bout was announced on 21 December to fight Briton Jack Massey (20-1-0, 11 KOs) for the undercard of the Chris Eubank Jr vs. Liam Smith on 21 January 2023 at Manchester Arena in England under Boxxer Promotions, on pay-per-view.

The headline for the event, billed as Day of Reckoning was Anthony Joshua vs. Otto Wallin, with Parker in the co-feature bout against former WBC champion Deontay Wilder (43-2-1, 42 KOs) in a 12-round non-title heavyweight fight.

[240] After the official press conference, Riyadh Season agreed terms with DAZN to broadcast the event on their pay-per-view platform in the UK, US and other worldwide markets.