He switched to grappling in 1991, moving to a Judo club where he was coached by sensei Miura.

Cassio was exposed to more of the self-defence aspect of  jiu-jitsu through Professor Sardella, a member of the Federal Police.

[3] Werneck fought in the Southern California Pro-Am Invitational 2003, where he beat Jeff Newton in the opening round before losing to Rener Gracie in the quarter-final.

The match with Gracie drew attention due to a controversial finish, where Werneck claimed that he did not tap.

[5] Athletes such as Randy Couture, Frank Mir, Dan Henderson and Urijah Faber have also trained under Cassio at his Sacramento location.