Harry Kane at last stops Man U player (5)
I believe the answer is:
beset
'harry' is the definition.
(I know that harry can be written as beset)
'kane at last stops man u player' is the wordplay.
'at last' indicates one should take the final letters.
'stops' means one lot of letters goes inside another (stopping can mean blocking a gap).
'man u player' becomes 'Best' (Manchester United footballer George Best).
The last letter of 'kane' is 'e'.
'e' inserted within 'best' is 'BESET'.
(Other definitions for beset that I've seen before include "Beleaguer" , "Press" , "Assail - surround" , "Surround (with problems)" , "Plagued" .)