Nearer the top of the class (5)
I believe the answer is:
upper
This clue is a double definition.
'nearer the top' is the first definition.
(I've seen this before)
'the class' is the second definition.
(upper class is a kind of class)
'of' is the link.
(Other definitions for upper that I've seen before include "catcher of swans?" , "Amphetamine pill" , "Higher; more northerly" , "The higher of two, berths perhaps" , "Higher; part of shoe" .)