Miami Open: Nadal and Djokovic march to quarterfinals

Nadal faced virtually no resistence from Ukrainian Alexandr Dolgopolov in a 6-1 6-2 victory, winning 86 percent of first service points and did not face a single break point. Dolgopolov had just won his rain-delayed three setter with Frenchman Jo-Wilfried Tsonga a few hours earlier.The Spanish world number one will face Czech Tomas Berdych, a 6-3 2-6 7-6 victor over German Florian Mayer, in the quarterfinals. Djokovic remains unbeaten in 2011, chalking up 21 successive wins, and that record was never in danger against fellow Serb Viktor Troicki in a straightforward 6-3 6-2 win. The world number two was comfortable throughout and will now face South African Kevin Anderson in the last eight.Roger Federer was due to face Belgiums Olivier Rochus later on Tuesday, but with rain delaying the evening session and with Maria Sharapova slugging it out with Alexandra Dulgheru for three and a half hours on the stadium court before winning 3-6 7-6 (6) 7-6 (5), the mens pair did not take the stage until well after midnight.Federer and Nadal will face each other in the semi-finals should they both progress. Argentina Juan Martin Del Potro, still making his way back from lengthy injury problems, fell to American Mardy Fish 7-5 7-6 earlier in the day.Fish is now one win away from replacing Andy Roddick as the top ranked American after his hard-fought victory in front of a crowd that was heavily backing his opponent. Fish will overtake Roddick, who lost in his opening game here, should he beat Spains David Ferrer in the quarter-finals.