World Number 1 Roger Federer was made to work hard, before securing his place in the Semi Finals of the ATP Event in Doha.
Federer who also reached the Semi Finals last year, won the 1st set 6-2 against Ernest Gulbis of Latvia, however Gulbis to his credit hit back and won the 2nd set 6-4.
The 3rd set was a tense affair but Federer eventually held his nerve and came through it to seal a 6-2 4-6 6-4 victory and book his place in the last 4.
In the Semi Finals Federer will face Nikolay Davydenko of Russia, Federer lost to the Russian in the Semi Finals of the World Tour Finals in London a few weeks ago.
Davydenko went on to win the title when he beat Juan Martin Del Potro of Argentina in the title match.
Russian will be hoping that he can replicate that form tomorrow and cause another upset against the Swiss maestro.