This doesn't need to be done in a single match, it can be done over a number of matches.
What you want to do is is silence enemy Gods while they're doing an attack/ability with your 3.
Good Gods to target are the ones that have the long drawn out abilities.
Cabrakan - When he's slamming the ground in the giant circle
Bacchus - When he's doing the burp
Anubis - When he's shooting that cone spray of bugs
You can silence many different attacks/abilities those are just some really easy ones as they last a while.
You can't use this to silence ultimate attacks so don't even try.
To check progress outside of a match go to your profile and then the "Achievements" section, next go to "Combat Practice" witch is the one with the two swords.