Went into power for sport (8)
I believe the answer is:
speedway
'sport' is the definition.
(I've seen this before)
'went into power' is the wordplay.
'went' becomes 'peed' (both can mean urinated).
'into' means one lot of letters goes inside another.
'power' becomes 'sway' (sway is a kind of power).
'peed' going into 'sway' is 'SPEEDWAY'.
'for' acts as a link.
(Other definitions for speedway that I've seen before include "Dirt track motorcycle sport" , "Motor sport" , "Cycling track" , "Form of motorcycle racing" , "Dirt track motorcycle racing" .)