In the 2008 World Championship he qualified for the main stage, He beat Colin Mitchell 10–0, Lee Walker 10–9 Joe Delaney 10–5, David Gray 10–5, and then Dominic Dale 10–9 to become only the fourth 17-year-old player to qualify for the Crucible after Stephen Hendry, Ronnie O'Sullivan and Judd Trump. Liu was drawn to play O'Sullivan in the first round. Despite being 0–3 down, Liu came back in the first session and levelled at 4–4, before O'Sullivan eventually won the game 10–5. Liu was relegated from the Main Tour after the following season.