Poet, northern one, huge hit for Yankees? (4,3)
I believe the answer is:
home run
'huge hit for yankees?' is the definition.
(baseball term)
'poet northern one' is the wordplay.
'poet' becomes 'homer' (Homer is an example).
'northern one' becomes 'un' (can mean 'one' in Northern English dialects).
'homer'+'un'='HOME RUN'
(Other definitions for home run that I've seen before include "result of big hit in US" , "complete tour of bases" , "Good baseball hit" , "Baseball score" , "In baseball, it allows batter to move through all bases" .)