Selby claimed his first world ranking title at the Welsh Open on 17 February 2008, winning a close-fought final 9–8 against O'Sullivan after recovering from 5–8 behind. However, he could not reproduce his Crucible success from the previous season; despite going into the 2008 World Championship as one of the bookmakers' favourites for the title, Selby was defeated 8–10 in the first round by Mark King.