Set of drinks for stage of competition (5)
I believe the answer is:
round
This clue is a double definition.
'set of drinks' is the first definition.
(as in a round of drinks ordered at a bar)
'stage of competition' is the second definition.
(I've seen this before)
'for' is the link.
(Other definitions for round that I've seen before include "Encircling" , "Get applause" , "Approximate" , "Division of a boxing match - having a curved shape - drinks bought by one person" , "with 6D [SPARE TYRE]" .)