Opportunity to play in championship finally gone (7)
I believe the answer is:
opening
'opportunity' is the definition.
(opening is a kind of opportunity)
'play in championship finally gone' is the wordplay.
'play' indicates an anagram.
'finally' says to take the final letters.
The last letter of 'championship' is 'p'.
'in'+'p'+'gone'='inpgone'
'inpgone' with letters rearranged gives 'OPENING'.
'to' is the link.
(Other definitions for opening that I've seen before include "Gateway - opportunity" , "Opportunity, start" , "break" , "premiere" , "Vacancy" .)