Following a cagey encounter at the Estádio do Dragão, tensions flared with both sides involved in an on-field bust-up.
Out of nowhere, a Porto fan came in and pushed Pizzi, but he was quickly rushed away by security.
Check out the incident for yourself here:
ISTO É MUITO GRAVE!
— Benfica Adeptos 1904 (@BenficaAdeptos) 2 de dezembro de 2017
Adepto do FC Porto agride Pizzi em pleno relvado. pic.twitter.com/cQHDbo72eh
The game ended in a goalless draw, meaning Porto maintained their place at the top of the Liga Nos table.