Reportedly sank putt on, say, eighteenth and last (4,3)
I believe the answer is:
hold out
'last' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for hold out that I've seen before include "Continue to resist" , "Offer as inducement or resist capture" , "Stand firm" , "Endure, last" , "Offer - last" .)