They beat qualifiers' outstanding run (6)
I believe the answer is:
hearts
'they beat' is the definition.
(I've seen this before)
'qualifiers' outstanding run' is the wordplay.
'qualifiers'' becomes 'heats' (I've seen this in another clue).
'outstanding' is an insertion indicator (some letters standing outside or around others).
'run' becomes 'r' (cricket abbreviation).
'heats' enclosing 'r' is 'HEARTS'.
(Other definitions for hearts that I've seen before include "Card suits in bodies" , "Card suit and essential organs" , "Central parts" , "Vital organs in the pack" , "Scottish footballers" .)