DOHA (Reuters) - World number one Roger Federer had to play three sets to reach the Qatar Open semi-finals on Thursday, while number two Rafael Nadal had an easier ride when his opponent retired injured to put him in the last four. Swiss Federer survived a scare from 21-year-old Latvian Ernests Gulbis before winning 6-2 4-6 6-4 to progress to the ...

Rafael Nadal reached the semifinals of the Qatar Open after Steve Darcis of Belgium retired with a back problem Thursday while trailing 6-1, 2-0. Nadal, a two-time quarterfinalist in Doha, will meet Viktor Troicki of Serbia, who beat Lukasz Kubot of Poland 4-6, 6-4, 7-6 (1). "I am playing ...