Novak Djokovic, Roger Federer win in Dubau Duty Free quarterfinals Tomas Berdych, shown in a match last September, was among the four top seeds who posted straight-set wins Thursday in quarterfinal play of the Dubai Duty Free Tennis Championships. DUBAI, United Arab Emirates, Feb. 28 (UPI) -- World No. 1 Novak Djokovic dropped just three games Thursday in a quarterfinal match at the Dubai Duty Free Tennis Championships. Djokovic was joined by the tournament's other top seeds in posting decisive straight-sets wins. Djokovic will go against fourth-seeded Juan Marin del Potro in the semifinals while second-seeded Roger Federer, the tournament defending champion, meets No. 3-seeded Tomas Berdych. Djokovic's 65-minute outing was the longest match of the quarterfinals. Djokovic won the first seven games en route to a 6-0, 6-3 defeat of Andreas Seppi. He won 62 percent of the points in the match and lost only 16 points in eight games serving. Federer's 6-2, 6-2 win over Nikolay Davydenko capped the quarterfinals. Federer bettered Davydenko in that he lost eight points in eight service games in the 54-minute match. He is 19-2 lifetime versus Davydenko. Berdych handled Dmitry Tursunov 6-3, 6-2 and won 79 percent of the points on serve while del Potro eliminated Daniel Brands 6-4, 6-2, taking 78 percent of the points when serving.