Heading for the championship (5)
I believe the answer is:
title
I believe this is a double definition.
'heading' is the first definition.
(title is a kind of heading)
'the championship?' is the second definition.
(a championship is a sporting title)
'for' is the link.
(Other definitions for title that I've seen before include "The name of a work of art or book" , "Lord, sir or doctor, say" , "Identifying name" , "Legal document regarding transfer of ownership: appellation" , "Right - name - rank" .)