Siyabonga Nkosi netted a brace and Knowledge Musona and Bernard Parker also got onto the score sheet, while Khulegani Madondo scored the only goal for the home side.
Musona had a great chance to open the scoring in the fifth minute when he was played through by Nkhatha, but his shot was parried wide by Kapini.
In the 12th minute Bernard Parker latched onto a long ball from Siphiwe Tshabalala on the left but his low strike went narrowly wide of the far post.
Musona then headed over then headed over the crossbar from Tshabalala’s corner in the 22nd minute, while Njabulo Manqana shot wide of the upright at the other end four minutes later.
Chiefs had the last two chances of the half with Parker firing against the post in the 29th minute, while Tshabalala’s long range effort sailed just over the crossbar in the 41st minute.
Amakhosi threatened again in the first minute of the second half as Musona found Nkosi unmarked on the left, but his shot was blocked by Kapini.
The resulting corner caused more problems for the hosts as Nkhatha’s header was cleared off the line by Madondo, while Parker struck the crossbar from the rebound.
Usuthu were also denied twice in quick succession in the 52nd minute with Ayanda Dlamini and Msekeli Mvalo both seeing their shots blocked by Chiefs defenders.
The opening goal eventually arrived three minutes later as Nkosi fired past Kapini from outside the box after receiving a pass from Tshabalala.
Chiefs doubled their lead in the 61st minute with Musona burying the rebound after Tshabalala’s shot was parried into his path by Kapini.
Usuthu also created an opening in the 67th minute when Ayanda Dlamini’s cross found Nkosinathi Mthiyane’s in the box, but he sent his header over the crossbar.
The visitors scored their third goal of the match in the 80th minute with Parker chipping the ball past Kapini after the goalkeeper was unable to hold on to a shot from Nkhatha.
Substitute Sithembiso Ngcobo almost pulled one goal back four minutes later when he met Ayanda Dlamini’s cross at the near post but his header struck the upright.
Chiefs extended their lead even further in the 86th minute as Nkosi poked the ball past Kapini after he was slipped through by Musona.
Usuthu did eventually find the back of the net in the fourth minute of added time as Madondo’s shot had the better of Itumeleng Khune following a wicked deflection from Mthiyane.
Scorers:
AmaZulu (0) 1 (Madondo 90+4’)
Kaizer Chiefs (0) 4 (Nkosi 55’ 86’, Musona 61’, Parker 80’)
Teams:
AmaZulu: Kapini, Macala, Hlanti, Mvalo, Nyadombo, Madondo, Dlamini G, Manqana (Ngcobo 66’), Mthiyane, Ndulula, Dlamini A
Kaizer Chiefs: Khune, Gaxa, Mashamaite, Mathoho, Masilela, Katsande (Nkosi 46’), Dladla (Bukenya 82’), Tshabalala, Musona (Rusike 88’), Parker, Nkhatha