At last, first-rate Mason Greenwood scores goals (4)
I believe the answer is:
ends
'scores goals' is the definition.
'ends' can be an answer for 'goals' ('end' can be a synonym of 'goal'). I am not sure about the 'scores' bit.
'at last first-rate mason greenwood' is the wordplay.
'at' says to put letters next to each other.
'last' becomes 'end'.
'first-rate mason greenwood' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'end' next to 's' is 'ENDS'.
(Other definitions for ends that I've seen before include "Rooms in bothy" , "They may be made to meet!" , "Send to conclusions" , "Finishes (loose or dead, perhaps?)" , "Brings to a close" .)