Turn funny having drunk port and act without restraint (3,4)
I believe the answer is:
run riot
'act without restraint' is the definition.
(I've seen this before)
'turn funny having drunk port' is the wordplay.
'funny' is an anagram indicator.
'having drunk' indicates putting letters inside.
'port' becomes 'rio' (I've seen this before).
'turn' with letters rearranged gives 'runt'.
'runt' enclosing 'rio' is 'RUN RIOT'.
'and' acts as a link.
(Other definitions for run riot that I've seen before include "Behave unrestrainedly" , "behave in unrestrained way" , "Behave in uncontrolled way as mob might" , "Raise hell" , "Of mob, throw off all restraint" .)