Novak Djokovic battled back for a three-set win over Marcos Baghdatis to book his place in the semi-finals of the Swiss Indoors in Basle.
The top-seeded Serbian struggled in the opening set, dropping his serve twice, but rallied in the next before easing away to a 2-6 6-2 6-3 win - his 67th of an extraordinary season that has seen him rise to become world number one.
Djokovic's victory in one hour and 39 minutes sets up an encounter with world number 32 Kei Nishikori of Japan in tomorrow's semi-finals.
Nishikori progressed in unconvincing fashion after combining for a remarkable 13 breaks of serve in his match with Mikhail Kukushkin of Kazakhstan.
The result could have gone either way with neither player looking comfortable on his own serve, but ultimately Nishikori prevailed 6-4 5-7 6-4 after two hours and 40 minutes.
Defending champion Roger Federer is also through to the last four after comfortably defeating Andy Roddick of the United States in their quarter-final tie.
Swiss star Federer, the world number four, has met Djokovic in the final of his hometown event for the last two years and stayed on course for another meeting with the world's top player after seeing off Roddick 6-3 6-2.
Federer will play fellow Swiss Stanislas Wawrinka in the semi-finals after the world number 19 defeated Florian Mayer of Germany 6-2 6-2.