A soccer team's turning point (4)
I believe the answer is:
axis
'turning point' is the definition.
(I've seen this before)
'a soccer team's' is the wordplay.
'soccer team's' becomes 'XI's' (a football team, from Roman numerals for 11).
'a'+'xis'='AXIS'
(Other definitions for axis that I've seen before include "Spotted deer" , "Line about which to rotate" , "Spindle - German/Italian alliance - deer" , "Line through the middle" , "Supposed political alliance" .)