Competitions set to run with man well organised (11)
I believe the answer is:
Here is my best explanation:
'competitions' is the definition.
(tournament is a kind of competition)
'set to run with man well organised' is the subsidiary indication.
'with' means one lot of letters go next to another.
'well organised' indicates anagramming the letters.
'settorunman' with letters rearranged gives 'tournaments'.
(Another definition for tournaments that I've seen is "Jousting events".)