Cricket side at Oval scored smoothly (6)
I believe the answer is:
legato
'scored smoothly' is the definition.
(I've seen this before)
'cricket side at oval' is the wordplay.
'cricket side' becomes 'leg' (I've seen this before).
'oval' becomes 'O'.
'leg'+'at'+'o'='LEGATO'
(Other definitions for legato that I've seen before include "In a smooth and flowing manner (music)" , "Played smoothly" , "Smoothly-flowing" , "Don't play roughly" , "Musically smooth" .)