The Ospreys suffered a fourth successive defeat in the Guinness PRO14 as they came unstuck 44-25 against the Cheetahs in Bloemfontein.
In contrast, the Cheetahs climbed to second place behind Glasgow in Conference A following a bonus-point victory that continued their recent resurgence following a stuttering start.
Despite wiping out a 15-point deficit to lead just before half-time, the Ospreys fell to a resounding defeat as their poor start to the season continued.
Cheetahs hooker Torsten van Jaarsveld and wing Makazole Mapimpi each scored two tries, while there were also touchdowns for flanker Paul Schoeman and centre Francois Venter, with Ernst Stapelberg kicking 12 points and William Small-Smith adding the final conversion.
Van Jaarsveld crossed twice during the opening 19 minutes as the Ospreys endured a testing start, but Wales scrum-half Rhys Webb got them moving on the scoreboard with a try that his international half-back partner Dan Biggar converted.
It launched a strong spell for the Welsh side, with substitute Kieron Fonotia crossing shortly afterwards, while another Biggar conversion and penalty put the Ospreys ahead before Mapimpi crossed just before the break and Stapelberg converted.
A Biggar penalty early in the second period cut the deficit, but the Cheetahs had plenty left in the tank, and they pulled away as Stapelberg kicked a penalty before Schoeman, Mapimpi and Venter crossed for tries.
Small-Smith converted Venter's score, and although Dan Evans claimed an Ospreys consolation try, it proved another miserable league outing for the Swansea-based side.