Put pressure on relations of Russian poet (7)
I believe the answer is:
pushkin
'russian poet' is the definition.
(I've seen this before)
'put pressure on relations' is the wordplay.
'put pressure on' becomes 'push' (I can't explain this - if you can you should give a lot more credence to this answer).
'relations' becomes 'kin' (I've seen this before).
'push'+'kin'='PUSHKIN'
'of' is the link.
Can you help me to learn more?
(Other definitions for pushkin that I've seen before include "As writer" , "Russian poet, author and dramatist" , "Boris Godunov poet" .)