Title-holder takes tea with politician (5)
I believe the answer is:
champ
'title-holder' is the definition.
('champ' can be a synonym of 'title-holder')
'tea with politician' is the wordplay.
'tea' becomes 'cha' (cha is a type of tea).
'with' says to put letters next to each other.
'politician' becomes 'mp'.
'cha'+'mp'='CHAMP'
'takes' is the link.
(Other definitions for champ that I've seen before include "use teeth?" , "Mashed potato with scallions" , "Top sportsman" , "Munch noisily; winner" , "Bite - victor (abbr)" .)