An entire floor was destroyed of the 25-storey building.
Johannesburg Emergency Services spokesperson, Robert Mulaudzi said the fire broke out at around 2am on the sixth floor in the office building on Smit Street.
The man, who had been trapped for hours was rescued at about 8am and was taken to Milpark Hospital for assessment.
Mulaudzi said no one was injured during the incident. He added that the cause of the fire was still unknown, however a team of investigators would determine whether the building was safe for usage and what caused the fire.
Smit Street was closed off to traffic and Metro police were diverting motorists into Harrison Street, with Bree and Jorissen Streets available as alternative routes.
Employees who had arrived for work, gathered outside the building as they watched smoke coming from the offices.
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