The Team of Choice had their chances on the night, but Dumisani Zuma's strike five minutes into the second half was enough for Amakhosi to claim victory.
Early on, it had been Maritzburg keeper Richard Ofori who did well to keep out Leonardo Castro's stinging shot, although the visitors were fortunate that Bernard Parker missed the target on the rebound.
At the other end, the Team of Choice were giving the home defence plenty of work and a seventh minute corner Mxolisi Kunene resulted in Chiefs defender Siphosake Ntiya-Ntiya skewing the ball towards his own goal, before goalkeeper Bruce Bvuma tipped it over the bar.
United also had a good chance to score nine minutes before half time when Mohau Mokate broke through the Amakhosi defence and laid off the ball to Fortune Makaringe, but Bvuma was up to the task with a sharp stop.
It then took some breathtaking defending from Nazeer Allie to keep the Soweto giants from scoring just ahea of half time as he raced back to clear Khama Billiat's header off the line before blocking the follow-up from Zuma.
Maritzburg had a great chance to take the lead just after the restart when Yannick Zakri flicked on for Mokate, but he slotted the ball past the on-rushing Bvuma and wide of goal.
The KZN side were to suffer a suck-punch shortly afterwards as Chiefs took the lead when Castro played in Zuma, who curled a shot into the top corner.
The Team of Choice had Amakhosi under pressure for the remainder of the game, but struggled to create too many clearcut chances for an equaliser.
They did come close 15 minutes from time when during a goalmouth scramble, Makaringe had two shots blocked in succession, before Bvuma saved at the feet of Kunene.
Kunene was also close to finding a goal in added time when he arrived at the back-post to meet a Deolin Mekoa cross, but Chiefs defender Kgotso Moleko got back to put the Maritzburg winger off.
Coach Eric Tinkler and his men now turn their attention to Tuesday night's clash with Mamelodi Sundowns at the Harry Gwala Stadium.
Kaizer Chiefs: Bvuma; Mphahlele, Moleko, Cardoso, Zuma, Maluleka, Zulu (Katsande 26'), Ntiya-Ntiya, Billiat (Ngcobo 46'), Castro (Moon 80'), Parker.
Maritzburg United: Ofori; Xulu, Sanoka, Allie, Kunene, Makaringe, Timm, Shandu (Mekoa 57'), Ndlovu, Mokate (Moseamedi 59'), Zakri (Kateregga 70').