Sapsford left school at the age of 16 and started a building apprenticeship. After finishing his apprenticeship, he left for Western Australia to work on a farm for a year. While there, he played Australian rules football at club level, picking up skills that proved to be helpful in the next phases of his rugby career. After his return to New Zealand, he started playing rugby again and represented Mid Canterbury in the Heartland Championship in 2016.[4][5]
Following Sapsford's season playing for Mid Canterbury, he was offered a Wellington Rugby Academy contract and played two seasons for the Wellington Development team.[6][7]
On 4 August 2019, Sapsford was named in the Hawke's Bay squad for the 2019 Mitre 10 Cup season.[9] He made his debut for the Magpies on 11 August 2019 against Manawatu and scored his first try for the province on 28 September 2019 in their game against Bay of Plenty.[10][11]
Sapsford was again named in the Hawke's Bay squad for the 2020 and the 2021 season.[14][15] During the 2020 Mitre 10 Cup season, Sapsford helped the Magpies win the Ranfurly Shield,[16] successfully defend the Shield three times and win the Mitre 10 Cup Championship, thus securing a well-deserved promotion to the Premiership division.[17] The Magpies held on to the Shield during the entire 2021 Bunnings NPC season – winning all six Ranfurly Shield defences[18] – and finished the regular season at the top of the Premiership table. They missed out on a spot in the Premiership Final after a 27 – 33 semi-final loss to Tasman.[19] In the regular season game against Manawatu on 30 October 2021, Sapsford scored a hat-trick in an eye-catching performance.[20]
From 2017 to 2019, Sapsford played several games for the Hurricanes Development team.[21][22][23] However, it was eventually an AustralianSuper Rugby franchise that offered him a contract. On 3 November 2021, the Brumbies announced that they had signed Sapsford on a two-year deal.[24] He made his Super Rugby debut for his new team on 20 February 2022 against the Western Force.[25] Sapsford scored his first Super Rugby try for the Brumbies on 2 June 2023 against the Rebels.[26]
On 13 June 2023, the Brumbies announced that Sapsford had re-signed with the franchise for another season.[27]
All in all, despite being part of the 2020 and 2021 All Blacks Sevens squad, Sapsford only had the opportunity to play for the team in warm-up matches against the Australian Sevens team during the Trans-Tasman Sevens tournament in May 2021.[35]
On 5 July 2023, Sapsford was named in the Australia A squad for a one-off match against Tonga. He qualifies for Australia on ancestry grounds via his mother.[36] He made his debut for Australia A on 14 July 2023, coming onto the field in the 56th minute of the game. Australia lost the game to Tonga 21–27.[37] In November 2024, he played two games for the team (then named Australia XV) against Bristol Bears and England A.[38]