After arriving at a driveway behind a used car yard, Kalepo asked for the windows to be wound up and paid the woman $40.
However, when she removed a condom for Kalepo to wear he pushed her hand away and said: "I'm not having that."
Kalepo forced himself onto her, holding her down using his forearm across his chest.
He then raped her.
Once Kalepo climbed off the woman, she activated her personal safety alarm which she kept attached to her skirt and carried with her while working.
A loud high-pitched noise screeched inside the car - sending Kalepo to scramble for his pants.
But before he left he stood at the door of the woman - preventing her escape. He told her to turn the alarm off.
She couldn't, which agitated Kalepo who punched her in the face and dislodged the alarm before throwing it away.
As the woman ran Kalepo reached out and grabbed the strap of her handbag in an effort to steal it.
But she refused to let go and the pair struggled over it before Kalepo pulled her hair, pushed her to the ground and again punched her in the face before driving away.
Suffering facial injures and wounds to her leg, the woman then made her way back to Hopetoun St where her ex-partner was.
Kalepo, who declined to talk to police when arrested years later, has previous convictions of a similar nature, the court heard.
The Crown may seek preventive detention when Kalepo, who is in custody, is sentenced in February.