Mark Allen squandered a 4-2 lead as he was edged out 5-4 by Shaun Murphy in the last 16 of the Shanghai Masters.
Murphy won the opening frame with a break of 102 but runs of 53, 58 and 100 helped Allen move into a 4-2 lead.
A 143 clearance, the highest break of the tournament so far, and a further 77 from Murphy made it 4-4 and the Englishman also took the final frame.
Murphy's victory earns the 2005 World Championship a quarter-final meeting with Mark Selby.
Murphy fought back from 4-1 down to beat Dominic Dale in the previous round.