Bash opening an event in Ring with rough slapstick comedy
I believe the answer is:
knock about
'rough slapstick comedy' is the definition.
'knock about' can be an answer for 'rough' (thesaurus). I'm unsure of the 'slapstick comedy' bit.
'bash opening an event in ring' is the wordplay.
'bash' becomes 'knock' ('knock' can be a synonym of 'bash').
'opening' says to take the initial letters.
'event in ring' becomes 'bout' (I can't explain this - if you can you should believe this answer much more).
The first letter of 'an' is 'a'.
'knock'+'a'+'bout'='KNOCK-ABOUT'
'with' is the link.
(Another definition for knock about that I've seen is " Boisterous - wander aimlessly".)