Masters exam's cracked by one with spirit (9)
I believe the answer is:
originals
'masters' is the definition.
('original' can be a synonym of 'master')
'exam's cracked by one with spirit' is the wordplay.
'exam's' becomes 'oral's' (spoken academic test).
'cracked by' indicates putting letters inside (inserted letters go into a gap or crack).
'one' becomes 'i' (Roman numeral).
'with' means one lot of letters go next to another.
'spirit' becomes 'gin' (alcoholic spirit).
'i'+'gin'='igin'
'orals' going around 'igin' is 'ORIGINALS'.
(Another definition for originals that I've seen is " cards".)