Outclass as Spurs thrashed (7)

I believe the answer is:

surpass

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'outclass' is the definition.
(thesaurus)

'as spurs thrashed' is the wordplay.
'as spurs' can be anagrammed to 'SURPASS'.
Though, I am unsure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for surpass that I've seen before include "Be better than (another)" , "supply best" , "Be better than (own best)" , "Outdo" , "Transcend" .)

I've seen this clue in The Sun.

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