Day's 2007/2008 season started with an appearance in the final of the Shanghai Masters; Day led his practise partner Dominic Dale 6–2 after the first session, but eventually succumbed to a 6–10 defeat. After failing to progress past the last 16 in the next three tournaments, he reached the semi-finals of the China Open, beating Matthew Stevens, Ken Doherty and Mark Williams before he was beaten by Stephen Maguire 5–6, denying him a place in the final. Day made it through to the quarter-finals of the World Championship for the first time in his career by beating Irishman Michael Judge 10–6 and the defending champion John Higgins 13–9 in one of the best wins of his career, before losing 7–13 to Stephen Hendry. His consistent performances took him up to 8th place in the rankings.