The goal was scored by a header from Ricardo Katza that took a deflection off the leg of Tshepo Motsoeneng to go into his own net.
The match was even in the possession stakes with both teams having some good scoring opportunities, poor finishing costing both sides.
In the 8th minute United should have taken the lead when a cross found Fikru Tefera unmarked in the box, he headed the ball past the upright from close-range.
AmaZulu should have scored when Dumisani Ngwenya drilled a right-footed from close over the bar in the 37th minute.
Effort Sithole nearly scored when his long-range shot went narrowly past United’ goal post on the stroke of halftime.
The goal was scored in the 49th through a header from Ricardo Katza, from a corner, which took a deflection off the leg of keeper Tshepo Motsoeneng to go into his own net to give United the lead.
A minute later United should have increased their lead but Dennis Masina hammered the ball over the bar from around 10-yards out.
John Moshoeu had a free kick brilliantly saved out of the top corner by keeper Denis Onyango in the 78th minute.
The win lifts United to mid-table on 9 points while AmaZulu are in the top half on 11 points.