Crossword Genius

Mushroom first one to go in basket? (10)

Ross

I believe the answer is:

balloonist

'one to go in basket?' is the definition.
(someone travelling in a hot air balloon's basket)

'mushroom first' is the wordplay.
'mushroom' becomes 'balloon' (both can mean grow very quickly).
'first' becomes 'ist' (ist resembles 1st).
'balloon'+'ist'='BALLOONIST'

I've seen this clue in The Times.
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