World No 1 Novak Djokovic advanced to the semi-finals of the Dubai Duty Free Tennis Championships without hitting a ball on Thursday.
Djokovic was due to face Mikhail Youzhny in the quarter-finals, only for the Russian sixth seed to be forced to pull out of the contest due to illness.
The Serb will face fourth seed Roger Federer in the last four.
Federer recovered from an early deficit to thrash Lukas Rosol 6-2 6-2 in their quarter-final, winning 12 of the last 14 games to complete victory in just 58 minutes.
For the fourth set in a row Federer lost his opening service game to fall 2-0 behind, but he promptly broke back to love and won six games in a row to take the set.
The Swiss veteran had to save a break point to avoid losing his first service game in the second set, but then broke Rosol twice more to complete a routine success.
The other semi-final will see Germany's Philipp Kohlschreiber take on second seed Tomas Berdych after Kohlschreiber recorded the 300th match win of his career by beating wildcard Malek Jaziri of Tunisia 6-2 6-3.
"It's always great to win many matches on the tour, especially a few rounds in a row," Kohlschreiber said. "I think I produced a very solid and good performance today. It's great that I have 300 victories under my belt."
One break of serve in each set was enough for second seed Berdych to beat Frenchman Jo-Wilfried Tsonga 6-4 6-3.