Excel as held by disorganised Spurs (7)
I believe the answer is:
surpass
'excel' is the definition.
(synonyms)
'as held by disorganised spurs' is the wordplay.
'held by' indicates putting letters inside.
'disorganised' indicates anagramming the letters.
'spurs' with letters rearranged gives 'surps'.
'as' put inside 'surps' is 'SURPASS'.
(Other definitions for surpass that I've seen before include "Excel" , "Be better than (own best)" , "Outstrip" , "Transcend" , "Go one better" .)