Raised game and beat friend, of course (9)
I believe the answer is:
naturally
'of course' is the definition.
(synonyms)
'raised game and beat friend' is the wordplay.
'raised' is a reversal indicator (going up in a down clue).
'game' becomes 'RU' (rugby union).
'and' says to put letters next to each other.
'beat' becomes 'tan' (tan can mean to beat or hit).
'friend' becomes 'ally' (an ally is a friend or supporter).
'ru'+'tan'='rutan'
'rutan' back-to-front is 'natur'.
'natur'+'ally'='NATURALLY'
(Other definitions for naturally that I've seen before include "As a matter of course" , "Unforced" , "Occurring normally, not artificially" , "as anticipated" , "as normal" .)