Thulani Gumede scored the only goal of the game with 20 minutes remaining as the home team secured their fifth league win of the season.
Having already suffered defeats to Stellenbosch and Soweto rivals Orlando Pirates in yeh space of four days, Amakhosi were determined to arrest their slide in KZN.
They however received a blow just before kickoff when captain and defender Miguel Inacio withdrew from the starting line-up with an injury.
The hosts should have taken the lead in the first half when Sanele Barns' shot was parried by goalkeeper Bruce Bvuma but Lundi Mahala sent his effort wide from eight yards.
The second half followed the same pattern with the Natal Rich Boys seeming the more determined to attack and grab the ascendancy.
Richards Bay's efforts were rewarded in the 69th minute when, following a counter-attack, Barns was in space down the right after slip by Chiefs defender Bradley Cross.
The winger picked put Gumede with a low ball across the face and the forward did well to compose himself before finishing past Bvuma.
Gumede had an opportunity to put the game to bed in stoppage-time when he was one-on-one with Bvuma but the shot-stopper denied the home striker.
Richards Bay ended the game on the front foot with Bvuma forced into another save to thwart substitute Wandile Ngema.
Orbit College gave their survival chances a timely shot in the arm on Tuesday as they beat TS Galaxy, while Stellenbosch failed to break into the Betway Premiership's top half.
Mamelodi Sundowns will look to strengthen their challenge for the Betway Premiership crown when they host Golden Arrows at Loftus Versfeld Stadium on Wednesday.
Richards Bay co-coach Papi Zothwane is determined to guide his side to all three points at home against Kaizer Chiefs on Tuesday night as their battle against relegation intensifies.
Monnapule Saleng was delighted to make an impact on his Mamelodi Sundowns debut in the 3-1 Betway Premiership victory over Sekhukhune United at the weekend.
