The 37 year-old, who had only previously lost four times in 43 bouts, hit the canvas three times in the contest before being halted by Mulovhedzi and subsequently surrendering his green belt in the process.
Mulovhedzi, 28, boasted a timid record of 9-7-3 having lost all seven in his first eleven contests, but has since gone on a run that saw the new champion win the South African title in an unbeaten run stretching back to 2009.
In the co-feature at the East London International Convention Centre, Lwandile Sityatha clung on to his super flyweight version with the IBO, when in reality, the 27 year-old should have been waking up without his champion status.
Sityatha was out-foxed by three-weight IBO title holder Gideon Buthelezi over the twelve round duration but scraped home with a highly debatable split decision to retain his belt for a third time. Buthelezi, 29, deserved a lot more than the 115-113 carded by a single judge as Sityatha was declared the winner by an unbelievable margin of 117-111 on one scorecard and 115-113 on another.
A rematch seems an inevitability if there is any lasting justice for the challenger.