Crossword Genius

Convincingly toppled leader in seventies denied last drink (3,4,2)

Ross

I believe the answer is:

all ends up

'convincingly' is the definition.
('all ends up' can mean 'completely')

'toppled leader in seventies denied last drink' is the wordplay.
'toppled leader in seventies' becomes 'Allende' (Salvador Allende, Chilean president 1970-1973).
'denied last' means to remove the last letter (the word is denied its last letter).
'drink' becomes 'sup' (to sup is to drink).
'allende' with its last letter removed is 'allend'.
'allend'+'sup'='ALL ENDS UP'

I've seen this clue in The Times.
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