World tennis number one Roger Federer won his way through to the semifinals of the Qatar Open on Thursday, after dropping a set against Ernests Gulbis of Latvia.
The score was 6-2, 4-6, 6-4.
Gulbis, who is ranked 90th in the world, hit 13 aces. Federer said after the match that the Latvian did not have the ranking he deserved.
"I know that Gulbis is the player with the most potential right now," he said.
In the next round on Friday, Federer faces Nikolay Davydenko of Russia who knocked out Ivo Karlovic of Croatia.
Also through to the semifinals is world number two, Rafael Nadal, whose opponent, Steve Darcis of Belgium, retired with a back problem in the second set. He will meet Viktor Troicki of Serbia, who won his place at the expense of Lukasz Kubot of Poland.
swissinfo.ch and agencies