Supporters groan -- it stops play (12)

I believe the answer is:

protagonists

'supporters' is the definition.
('protagonist' can be a synonym of 'supporter')

'groan it stops play' is the wordplay.
'play' indicates anagramming the letters.
'groan'+'it'+'stops'='groanitstops'
'groanitstops' is an anagram of 'PROTAGONISTS'.

I've seen this clue in The Telegraph.

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