At No.1, he may have no peer (6)
I believe the answer is:
opener
'at no 1 he may' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'no peer' is the wordplay.
'no peer' can be anagrammed to 'OPENER'.
Though, I am not clear how the anagram is indicated.
'have' is the link.
Can you help me to learn more?
(Other definitions for opener that I've seen before include "First event in a series" , "First goal in game" , "leading batsman" , "introduction" , "See 1" .)