Jockey reported winning, bagging Cheltenham's first trophy (5,3)
I believe the answer is:
ryder cup
'trophy' is the definition.
(I've seen this before)
'jockey reported winning bagging cheltenham's' is the wordplay.
'jockey' becomes 'rider' (horse rider).
'reported' shows a homophone (sound like).
'winning bagging cheltenham' becomes 'cup' (I can't justify this - if you can you should believe this answer much more).
'rider' sounds like 'ryder'.
'ryder'+'cup'='RYDER CUP'
'first' acts as a link.
Can you help me to learn more?
(Other definitions for ryder cup that I've seen before include "US-Europe golf event" , "Golfing contest" , "Prize for golfers" , "trophy" , "Sporting event" .)