Shopper turned up, requiring first and second drink (9)

I believe the answer is:
purchaser
'shopper' is the definition.
(I've seen this before)
'turned up requiring first and second drink' is the wordplay.
'turned' says the letters should be written backwards.
'requiring first' becomes 'r' (1st letter of 'requiring').
'and' is a charade indicator (letters next to each other).
'second drink' becomes 'chaser' (I've seen this before).
'up' backwards is 'pu'.
'pu'+'r'+'chaser'='PURCHASER'
(Other definitions for purchaser that I've seen before include "Shopper" , "he's bought" , "Punter" , "customer" , "One who buys something" .)