The Durban team were heavily indebted goalkeeper Mbongeni Mzimela, who made several fine saves to deny a Dikwena team who probably deserved a share of the spoils.
Stars started strongly, with Edward Williams almost scoring in the second minute with a close range effort that was blocked by Mzimela.
Three minutes later Ayanda Dlamini almost scored for the hosts, heading just over the target after meeting a cross from Ntokozo Sikhakhane.
AmaZulu began to boss the game in midfield, but Stars were still a potent force going forward and on 28 minutes the home side need Mzimela to keep out an Almiro Lobo shot from a corner kick. A second successive set piece then saw Phelelani Mpangase head an effort over the top.
Usuthu threatened twice in the latter stages of the first half, with new signing Gavin Hammers and striker Dlamini flashing long range efforts just off target.
Scoring chances were harder to come by in the second half, though Dlamini probably should have scored with his head just before the hour mark, while Andile Khumalo’s long range attempt was saved with relative comfort by Tapuwa Kapini.
On 80 minutes Mzimela was again a hero for AmaZulu, making a fantastic double save to twice deny Nduduzi Nyanda.
And the goalkeeper’s exploits were not in vain, as two minutes into added time substitutes Goodman Dlamini and Mnyingwa combined, with the latter heading home the formers cross from close range to hand AmaZulu a slender victory.