Guardian article wins back support (5)
I believe the answer is:
angel
'guardian' is the definition.
(guardian angel)
'article wins back support' is the wordplay.
'article' becomes 'an' (indefinite article).
'wins back' becomes 'gel' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'support' says to put letters next to each other (in a down clue, some letters hold others up).
'an'+'gel'='ANGEL'
Can you help me to learn more?
(Other definitions for angel that I've seen before include "Theatrical backer" , "Sponsor" , "local to Islington" , "Theatre backer" , "Heavenely messenger" .)