Champ punched by this person in European city (6)
I believe the answer is:
munich
'european city' is the definition.
(German city)
'champ punched by this person' is the wordplay.
'champ' becomes 'munch' (both can mean to bite).
'punched by' means one lot of letters goes inside another (some letters punch a hole in others).
'this person' becomes 'I' (the person writing).
'munch' going around 'i' is 'MUNICH'.
'in' is the link.
(Other definitions for munich that I've seen before include "Bavarian city" , "South German city" , "Largest city of Bavaria" , "foreign city" , "Capital of Bavaria" .)