Champions not needing extra time, man — game of two halves, perhaps? (6)
I believe the answer is:
cliche
'game of two halves perhaps?' is the definition.
I can't tell whether this definition defines the answer.
'champions not needing extra time man' is the wordplay.
'champions' becomes 'cli' (I can't justify this - if you can you should give a lot more credence to this answer).
'not needing' suggests deleting specific letters.
'extra' becomes 'b' (abbreviation for 'bye' - cricket).
'time' becomes 'bc'.
'man' becomes 'he'.
'bc' with 'b' taken away is 'c'.
'cli'+'c'+'he'='CLICHE'
Can you help me to learn more?
(Other definitions for cliche that I've seen before include "Tired 21/12 [TURN OF PHRASE]" , "Nothing new in that, so to speak" , "One by one" , "Platitude" , "Overused expression" .)