ADJ

major
international, national, world
British, European, etc.
swimming, tennis, etc.

VERB + CHAMPIONSHIP

hold
The championships are to be held in Rome
compete in, take part in
Over thirty children will compete in the swimming championships
win
She has won four major championships in the last five years
lose

CHAMPIONSHIP + VERB

take place

CHAMPIONSHIP + NOUN

final, game, match, race
title, winner

PREP

at a/the ~
I saw him play at last year's tennis championship
in a/the ~
the teams in the championship

VERB + CHAMPIONSHIP

hold
Who holds the championship at the moment?
take, win
He's won the championship for the third time in a row
lose
regain
retain
She managed to retain the championship