[3] Nontshinga made his professional debut on 30 July 2017 at the age of 18, defeating Sandile Wessels in a third-round finish in East London.
[4] On 7 April 2019, he scored a first-round knockout over Adam Yahaya to win the vacant IBF International light-flyweight title in Port Elizabeth.
[8] Nontshinga suffered a swollen left eye early, but after knocking him down at the end of the fourth round, he dropped the veteran for good in the fifth with a right cross.
[9][10] After more than a year without a fight due to the COVID-19 pandemic, Nontshinga defeated Filipino prospect Christian Araneta in an IBF title eliminator in Port Elizabeth on 24 April 2021.
[11] Nontshinga faced the undefeated Hector Flores for the vacant IBF light flyweight title on 3 September 2022, following a seventeen-month absence from the sport, at the Centro de Usos Múltiples in Hermosillo, Mexico and was as such his first fight outside of his native South Africa.
[20] Eddie Hearn’s Matchroom Boxing confirmed on September 11, 2023, that Nontshinga would make a voluntary title defense against the #11 ranked IBF light-flyweight contender Adrian Curiel.