Grace joined St Helens in 2014, when he was only 17. Despite not making his first-team debut for St Helens until 2017, he was first picked to play for the Welsh international side in October 2015 when he came on as an interchange player in Wales' 14–6 victory over France.[6]
His first Super League appearance came on Good Friday, 14 April, 2017 in the derby match against Wigan where he scored a try on debut.[7] The following month he signed a new two-and-a-half-year contract with St Helens.[8] Since that moment, Grace was a regular in the St Helens side making 139 appearances by the end of the 2021 season and scoring 87 tries.[1] Among those matches have been two Challenge Cup finals. The first was the 2019 Challenge Cup Final defeat by Warrington at Wembley Stadium[9] The second was the 26–12 2021 Challenge Cup Final victory over Castleford.[10] During the 2021 Challenge Cup Grace was the leading try-scorer, scoring seven including a hat-trick against Huddersfield in the quarter-finals, and two in the semi-final against Hull FC.[11][12][13]
Grace has also played in three Super League Grand Finals as St Helens won the 2019, 2020 and 2021 Grand Finals.[14][15][16] On 5 July 2022, Grace signed a contract to join Rugby Union side Racing 92 in 2023.[17] On 2 August 2022, it was announced that Grace had ruptured his achilles during St Helens heavy defeat against Salford which would rule him out for the remainder of the 2022 Super League season.[18]
Grace signed for Top 14 side Racing 92 in 2022, but was ruled out with a significant achilles injury.[20] While recovering, Grace suffered a recurrence of the same achilles injury.[20]
Bath
Grace was released by Racing 92, and in November 2023 linked up with Premiership team Bath to continue his rehab.[21] Grace signed a short-term contract with Bath on 16 February 2024, and made his debut on 9 March 2024, in a friendly against Gloucester.[22][23] On 24 April 2024, Grace signed with Bath for the 2024–25 Premiership season.[24]