Mulenga won a silver medal at the 2016 African Region V Youth U20 Games in Luanda, losing to Ricardo Malajika of South Africa in the finals.[2] He reached the quarterfinals of the bantamweight event at the 2018 Commonwealth Games, where he won his first bout before suffering a loss to Mohammad Hussamuddin.[3] Mulenga won a featherweight bronze medal at the 2019 African Games in Rabat.[4] He won three straight fights before losing to the eventual gold medalist Mohamed Hamout in the semifinals.[5]