Defending champion Roger Federer reached the semi-finals of the Halle grasscourt championships on Friday without appearing on court as quarter-final opponent Lu Yen-Huen of Taiwan withdrew through injury.
Lu, who had self-deprecatingly announced that he faced a mission impossible against the Swiss former world number one when he said: "If I'm 150% and he's 100% I think I'd still lose", pulled out with a recurrence of a back problem.
Federer, a six-tine winner of the tournament, now faces Japan's world number 12 Kei Nishikori, who beat American Steve Johnson 6-1, 7-6 (7/4), for a place in the final.
Earlier, Philipp Kohlschreiber fought his way into the semi-finals by edging past fellow-German Dustin Brown 6-4, 5-7, 7-6 (18/16).
Kohlschreiber, who was on the losing end of a five-set marathon against Britain's Andy Murray at the French Open, prevailed after an epic third set tie-break against world number 85 Brown.
The defeat was a bitter disappointment for Brown, who had knocked out world number one Rafael Nadal the previous day.
Kohlschreiber, the 2011 champion, now plays 69th-ranked Alejandro Falla for a place in the final after the Colombian overcame another German Peter Gojowczyk 7-6 (7/4), 7-6 (7/2).
Wildcard Gojowczyk also saw his run come to an end in frustrating fashion, having claimed the scalp of third seed Milos Raonic of Canada in the previous round.
Story first published on: Friday, 13 June 2014 21:14 IST