Cry out, securing end of major punch-up (5)
I believe the answer is:
brawl
'punch-up' is the definition.
(I've seen this before)
'cry out securing end of major' is the wordplay.
'cry out' becomes 'bawl'.
'securing' means one lot of letters goes inside another.
'end of' indicates one should take the final letters.
The last letter of 'major' is 'r'.
'bawl' enclosing 'r' is 'BRAWL'.
(Other definitions for brawl that I've seen before include "Noisy crowd fight" , "Affray" , "Public punch-up" , "Unruly fight" , "Rough, noisy fight" .)