Try a lighter international competition (4,5)
I believe the answer is:
test match
'international competition' is the definition.
'test match' can be an answer for 'competition' (test match is a kind of competition). I am not sure about the 'international' bit.
'try a lighter' is the wordplay.
'try' becomes 'test' (synonyms).
'a lighter' becomes 'match' (match is a kind of lighter).
'test'+'match'='TEST MATCH'
Can you help me to learn more?
(Other definitions for test match that I've seen before include "International contest" , "sporting event" , "International (esp. cricket)" , "International meeting" , "International fixture" .)