Mark Selby saw his bid to win the Betfair German Masters ended at the quarter-final stage by Barry Hawkins.
The world number one, who had landed the UK Championship title in December and the Masters in January, was beaten 5-1 at Berlin's vast Tempodrom venue.
Kent cueman Hawkins, ranked 17th in the world, comfortably overcame Selby to set up a last-four showdown with Hong Kong's Marco Fu, who had recorded a 5-3 victory over Welshman Matthew Stevens.
The other semi-final will see Ali Carter and Neil Robertson do battle.
Carter, a semi-finalist at the UK Championship this season and World Championship runner-up last May, eased to a 5-2 win against Nottingham's Michael Holt.
Robertson, in contrast, was pushed all the way by his fellow former world champion Shaun Murphy.
Murphy fought back from 4-2 behind to draw level at 4-4 after impressive back-to-back breaks of 107 and 133.
But the Australian held his nerve in the deciding frame though, meaning the world number five could still yet land his first major title of the season at the weekend.