The defender first joined the Pretoria side from Academica in Portugal back in 2016.
Nascimento says he agreed to a new contract with the club so he could help them win their second Caf Champions League trophy.
"I feel very happy about the confidence Mamelodi Sundowns has shown in me and my football abilities. I want to thank the President, Dr. Patrice Motsepe, the Board and the Technical team with Coach Pitso," Nascimento told the Sundowns website.
"From the start, I was well-received by all the supporters and I to thank the supporters and my teammates for making me feel so welcome. My family and I are enjoying the country and I must certainly say that South Africa is my second home"
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