DUBAI, United Arab Emirates (AP) -- While top-seeded Novak Djokovic had a rest day when opponent Mikhail Youzhny became ill and withdrew from their quarterfinal on Thursday, Roger Federer had to play his way into their semifinal date at the Dubai Championships.
The fourth-seeded Federer, who has won this title five times, won his 40th match at the Dubai Championships with a 6-2, 6-2 win over Lukas Rosol of the Czech Republic.
Federer made a slow start, falling behind 2-0 but quickly rebounded by winning the next six games. In the second set, Federer broke serve in the third and fifth games.
''When you play someone for the first time, you never quite know what his best level is or his normal level is,'' Federer said. ''That's why you kind of keep pushing on, and that's also why I guess the score came out the way it did, because I never let go.''
Federer holds a slim 16-15 winning record over Djokovic. The Serbian, however, has beaten Federer in their last three matches, and nine of their last 12 meetings.
''He is in the semis, he's already played two matches, he's been here long enough for preparing, and he's fit enough for anything anyway,'' Federer said of Djokovic having a quarterfinal walkover. ''Every match you can get away from is a good one.
''For me, it was important also probably not to be out there for three hours. Then it would have been a disadvantage. But I think we're back on even terms for tomorrow.''
Playing in his fourth quarterfinal of the season, Kohlschreiber's 6-2, 6-3 win over Tunisian wild card Malik Jazirivictory was his 300th match-win on the ATP Tour.
Berdych holds a 7-1 winning record over Kohlschreiber.
''The record is one thing, but then always the match is going to start from zero,'' Berdych said. ''I have seen Philipp play here and he's playing really well.
''He's playing very aggressive, very confident, too.''
Berdych, who was a finalist last year, fought past fifth-seeded Jo-Wilfried Tsonga 6-4, 6-3.
Berdych was on a 10-match winning streak, which includes his win at the Rotterdam tournament two weeks ago.
The first set stayed on serve until Tsonga dropped his at love in the 10th game.
The second set was even more tightly contested. In the fifth game, Berdych faced four break points but held on. Tsonga surrendered his serve in the eighth game when he double-faulted on break point.
''It was very close,'' Berdych said. ''I faced many break points which was very tough, but that was really the key of today's game, that I managed to save them.''