The Champion of Champions format is different to most other tournaments.
There is an initial group stage before knockouts later on in the week.
There are eight seeded players at the event, of which two are placed into four groups.
Star man O’Sullivan won his group about Tuesday.
He defeated Stuart Bingham, who recently claimed the 1st Home Nations title of the season at the English Open last month, in his 1st match before seeing off John Higgins in the group decider.
The Rocket is now through to the semi-finals, where he will play Shaun Murphy.