The Urban Warriors were the better team throughout, as they jump to within two points of the top eight. Grant Margeman and Ndiviwe Mdabuka scored on the day for the hosts.
Margeman opened the scoring as early as the sixth minute, with the hard-working midfielder running onto a precise through ball by Travis Graham - steadying himself and firing through the legs of Mbongeni Mzimela. This was his third goal in South Africa's top-flight.
The Cape side continued to dominate the clash, but failed to make Dikwena pay as Prince Nxumalo missed a succession of chances.
Mbongeni Mzimela, the savior on two occasions for the Phokeng-based club, punched clear a Nxumalo's header attempt before saving with his feet in the 42nd minute - again to deny the KwaZulu-Natal born forward.
Dikwena showed more promise following the break, with Mosa Lebusa on hand to clear off-the-line four minutes into the second stanza.
Ajax Cape Town, though, still looked the better of the two sides with Nathan Paulse and Thabo Mosadi missing successive chances at the other end of the park.
The hosts, though, would finally double their advantage as Mdabuka's deflected shot bounced into the back of the net in the 66th minute.
Platinum Stars failed to deliver any serious goal threat in the closing stages as the Cape club returned to winning ways, to ease their relegation woes.