Upset person puts on ace 'Walk This Way' when drunk! (7)
I believe the answer is:
stagger
This clue could be a double definition.
'upset' is the first definition.
(thesaurus)
'person puts on ace walk this way when drunk' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
Can you help me to learn more?
(Other definitions for stagger that I've seen before include "Lurch; astound" , "Walk as though in danger of falling" , "bowl over" , "Reel - astound" , "Reel about; shock" .)