The victory over the Brazilians' second-stringers followed last week’s 2-1 win over Free State Stars, when Mohau Mokate and Devon Saal netted for United.
Saal was also on target against Sundowns, scoring the opening goal at the Harry Gwala Stadium before Rushine de Reuck completed the victory.
Coach Siya Mdluli's side are in action on Monday 25 September, when they play Golden Arrows at the Vosloorus Stadium.
The only other team to have won both their opening games is Bloemfontein Celtic.
COMMENT ON THIS STORY ON SOCIAL MEDIA
FADLU CALLS FOR 'PRAGMATIC' APPROACH
MTN8 SEMI FINAL TICKET OUTLETS
MDLULI GUNNING FOR ANOTHER STRONG MDC CAMPAIGN
SATURDAY’S GAME A CLEAN SLATE, SAYS SKIPPER
LOCAL DUO PRESENT MAYOR WITH PERSONALISED JERSEY
COME HELP US MAKE HISTORY - CHAIRMAN
MARITZBURG SIGN CAMEROON INTERNATIONAL STRIKER
TEAM OF CHOICE MAINTAIN PERFECT LEAGUE START
TRANSPORT FOR MTN8 CLASH IN TSHWANE
UNITED READY FOR URBAN WARRIORS
MARITZBURG OPEN LEAGUE ACCOUNT WITH THREE POINTS