Usuthu’s first chance at goal was instigated by Sibusiso Mabiliso’s run down the left which delivered a cross for Siphelele Sithebe who headed wide on five minutes.
Richards found a massive chance to go ahead but Michael Gumede failed to capitalise on Stanley Muishond’s delivery after 15 minutes.
Shortly, the opener came and it was AmaZulu’s Thapelo Nyongo with a cracking finish after collecting from the middle before running towards goal to beat Xolani Ngcobo with an outrageous strike.
Richards Bay tried to get a quick response, but Menzi Hlope fired over the top from close range after a loose ball in the box on 34 minutes.
As such, the Premiership outfit went to the tunnel in the lead poised for a stern second half in front of a boisterous home crowd.
The NFD side had another golden chance to get on the scoreboard, but Energy Murambadoro’s bravery put off Stanley Muishond who missed with a gaping net.
Veteran Mabhuti Khenyeza played a quick combination with Sithebe, but the latter shot straight at a starring Ngcobo who collected comfortably.
AmaZulu were close to doubling their tally, but Siphesihle Maduna’s dribbling to goal was undone by a wayward end product that sailed wide of Ngcobo’s reach on 74 minutes.
Cavin Johnson’s side held on in the closing minutes to clinch the second instalment of the KZN Premiers Cup ahead of their league opener next weekend.