Guimarães lost 3-1 to Chaves in the semi-final second-leg match with Zungu being introduced in the 54th minute in Chaves on Tuesday night.
The tie ended in a 3-3 draw, but Zungu's side won on the away goals rule as they had beaten Chaves 2-0 in the first-leg clash at home a month ago.
Zungu has established himself as one of Guimarães' key players since making his competitive debut for the club in December 2016.
Since then the 24-year-old player has received three man of the match accolades and he has made 17 appearances in all competitions thus far.
The winner between Portuguese giants Benfica and Estoril will face Guimarães in this season's final at the Estádio Nacional on the 28th of May 2017.