Mabhuti Khenyeza scored his first goal for the Brazilians, but two strikes in the space of five minutes from Sifiso Vilakazi and Diyo Sibisi handed the Cape side all three points.
Ajax were the first to get an effort in on target, with Aboubacar Fofana getting on the end of Franklin Cale’s cross and directing a looping header toward the top corner of the net, but Brian Baloyi tipped the ball over the crossbar.
The visitors were fortunate not to concede a penalty midway through the first half when Nazeer Allie tripped up Elias Pelembe.
Ten minutes later the Brazilians broke the deadlock through a former Urban Warriors player. Katlego Mphela picked out a good pass to give Khenyeza a clear sight of goal and the stocky striker provided a cool, side-footed finish past Hans Vonk.
Ajax responded well, putting the home side under pressure in the remainder of the first half. In the 40th minute the ball rebounded between two Sundowns defenders and almost gave Fofana a shooting chance, but Baloyi reacted sharply to come off his line.
Just over ten minutes into the second half Sundowns needed another good intervention in defence, this time from young centre-back Siyanda Xulu to block a fierce strike from Cale.
A short while later substitute Sifiso Vilakazi almost brought the visitors level with a snap volley on that flashed just the wrong side of Baloyi’s right-hand post.
However, the former Free State Stars man did find the target on 69 minutes. Diyo Sibisi drove down the left flank and provided a great cut-back for sub Cole Alexander – the youngster should have scored himself but saw his effort saved by Baloyi, only for Vilakazi to stab home the rebound.
And just five minutes later Ajax went into the lead. Sibisi capitalised on a poor defensive header from Innocent Mdledle to calmly finish past Baloyi.
On 80 minutes Felix Katongo almost made it 2-2 with a glancing header from Pelembe’s corner-kick, but Nhlanhla Shabalala cleared the effort off the goal line.