Champions were upset, sloping off to the rear (9)

I believe the answer is:

backswept

'sloping off to the rear' is the definition.
(sloping to the back or rear)

'champions were upset' is the wordplay.
'champions' becomes 'backs' (as verb - supports).
'were upset' becomes 'wept' (as in weeping when upset).
'backs'+'wept'='BACKSWEPT'

I've seen this clue in The Times.

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