Topple after a little Negroni and fizz as starters (9)
I believe the answer is:
antipasti
'starters' is the definition.
(I've seen this before)
'topple after a little negroni and fizz' is the wordplay.
'topple' becomes 'tip'.
'after' is a charade indicator (letters next to each other).
'little' says to take the initial letters.
'and' says to put letters next to each other.
'fizz' becomes 'asti'.
The initial letter of 'negroni' is 'n'.
'a'+'n'='an'
'tip' put after 'an' is 'antip'.
'antip'+'asti'='ANTIPASTI'
'as' is the link.
(Other definitions for antipasti that I've seen before include "first course" , "Italian eats" , "that's served in trattoria" , "Italian diner might offer these" , "Italian food selection" .)