A goal from Themba Zwane separated the two sides going into the break but Sphamandla Mlilo levelled minutes into the second period before Khama Billiat ensured all three points went back to Chloorkop.
There was an early suggestion that both sides may struggle with the wet conditions but Sundowns apapted quickest to the sodden turf and began to assert their authority.
As if a portend of things to come Percy Tau surged forward and forced Mbongeni Mzimela to get down and keep out a shot that threatened to sneak in at the near post.
It wasn't long until the deadlock was broken as Sundowns moved swiftly into an attacking area and Algerian fullback Fares Hachi pulled the ball back for Zwane to slot home fom 10-yards.
Minutes later Tau once again broke free and tried the cutest of finishes as he clipped the ball over Mzimela but it ghosted just wide of the upright.
Tau remained in the thick of things as he timed his run to perfection and put the ball on a platter for Anthony Laffor who could do nothing more than nudge it tamely towards goal via his thigh.
Approaching the half-hour mark Laffor's quick release of Billiat allowed the Zimbawean space in the box and with his effort having beaten the goalkeeper, Gerald Phiri was required to slide in and clear the ball off the line to his own detriment as he crashed into the post in the process.
With an assist already to his name Hachi whipped in a delightful ball that was met at the back post by a diving Anele Ngcongca but he could only steer his header wide of the upright.
Chances were at a premium for Stars and when Bongi Ntuli found the ball at his feet on the edge of the area the former Sundowns man skied his effort.
Denis Onyango was untroubled going into the break but Sundowns will have felt they should have capitalised on more of their chances.
In the second stanza the defending champions were made to pay for their profligacy in front of goal as Platinum Stars restored parity in the 49th minute.
The man to score was impressive young defender Mlilo who beat Onyango to a free-kick and directed it past the 'keeper via his head.
Dikwena were later presented with a chance that stemmed from Onyango's misdirected clearance but Abia Nale eventually slammed his effort into the side netting.
At the other end Tau demonstrated his incredible hang-time as he rose to get above Willem Mwedihanga but headed the ball inches over the crossbar.
Cavin Johnson decided to haul off Ndumiso Mabena and throw on young Gift Links and it almost paid immediate dividends as the substitute found himself in space and forced Onyango to save his fierce near-post shot.
With the game into the final 10 minutes Tau and Billiat combined expertly before the latter finished superbly past Mzimela to restore the Brazilians' lead.
Billiat had an opportunity late on to grab another as he again exchanged passes with Tau who played him through before Dikwena's stopper rushed out to deny him.
The win takes Mamelodi Sundowns to fourth on the Absa Premiership standings having moved ahead of SuperSport United on goal difference.