Having no side in rugby to beat upset supporter (9)

I believe the answer is:

naturally

I'm a little stuck... Click here to teach me more about this clue!

'having no side' is the definition.
I can't judge whether this defines the answer.

'rugby to beat upset supporter' is the wordplay.
'rugby' becomes 'RU'.
'to beat' becomes 'tan' (tan can mean to beat or hit).
'upset' says the letters should be written backwards.
'supporter' becomes 'ally' (an ally is a friend or supporter).
'ru'+'tan'='rutan'
'rutan' backwards is 'natur'.
'natur'+'ally'='NATURALLY'

'in' acts as a link.

Can you help me to learn more?

(Other definitions for naturally that I've seen before include "without medical assistance" , "Unforced" , "as you might expect" , "As a matter of course" , "Without affectation" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.