KickOff.com reported earlier on Wednesday that Sundowns had approached Usuthu for the South American forward.
Sundowns have now officially confirmed the arrival of the striker just one day before the transfer window slams shut.
AmaZulu have also confirmed that Bonginkosi Ntuli's loan move has now been made permanent.
"The club can confirm the acquisition of striker Bongi Ntuli from @Masandawana on a permanent deal while Emiliano Tade has gone in the other direction," AmaZulu tweeted.
The 30-year-old notched up seven goals and two assists in 19 appearances for Usuthu this season.