He wanted to make sure I was safe and then he let go, Letshego Zulu on Gugu's final moments
Mabaso was speaking at a memorial for Gugu Zulu at Kyalami Race Track in Johannesburg.
An emotional Mabaso described how, along with Gugu's wife Letshego, they climbed down the mountain from 8:30pm to 5am.
"Letshego, these words stuck with me. Letshego cried. When we reached the bottom, she said: 'This is the gentleman I dated. This is the gentleman I married. He wanted to make sure that I am safe before he let go. I was safe then he let go,'" explained Mabaso.
Watch: I will continue to keep the flag flying - Letshego Zulu promises Gugu
The memorial has seen friends and colleagues including those from the racing industry paying tribute to Zulu.
Zulu was part of the Trek4Mandela expedition which aimed to raise funds for girls who cannot afford sanitary pads.
Mabaso said that 3.6million pads have been collected and applauded Zulu's efforts.