MADRID (AFP) - Top seed Rafael Nadal and American Andy Roddick reached the Madrid Masters quarter-finals without hitting a ball on Thursday when their scheduled third round opponents pulled out with leg injuries. World number one Nadal went through courtesy of German Philipp Kohlschreibers decision not to play, a decision which left thousands of fans frustrated at not seeing their Spanish superstar on court at this troubled event.Almost simultaneously, sixth seed Roddick enjoyed the same gift when Russian Nikolay Davydenko pulled the plug before their scheduled late-night encounter.Meanwhile, Roger Federer stormed to a 6-2, 6-4 win over James Blake while Scot Andy Murray also coasted into the last eight with a 7-5, 6-1 victory over Spanish 16th seed Tommy Robredo. Federer said he was relieved that none of the top seeds had been affected by the injury plague. I wish that every match could be played out and be finished so the tournament is not going to suffer too much, said Federer. None of the great, great players had to pull out which is a good thing, which has happened before like in Paris (in 2008) when Rafa and I had to pull out which was kind of tough. Federer, aiming to lift his first title of the season, and keen to peak in time for next Sundays start of Roland Garros, was impressive against Blake, whose only win over the Swiss in ten meetings came at the Beijing Olympics.The Swiss second seed said his Thursday rout in just one hour was a completely different story. It didnt really feel like revenge on clay, said the 13-time Grand Slam winner. It was definitely not the quality of the tennis we played in Beijing. James struggled quite a bit today, but from my side it was pretty comfortable. I played OK and Im happy it was that easy. Federer saved the only break point he faced, broke three times and managed 20 winners. It was always going to be easier to serve well here due to the (500m) altitude, he added. James goes for a lot of shots so its always easier to ace players like him instead of other guys who just try to get it back. Federer next plays Roddick, whom he has beaten twice in 2009. Weve played so many times, its about time we played on clay, said Federer. Novak Djokovic completed a cleansweep for the top seeds, turning in a solid win over Italian Andreas Seppi 6-4, 6-4. He will next play Croatian Ivan Ljubicic who put out French eighth seed Giles Simon 3-6, 6-4, 6-3. Fourth seed Murray will face fifth seed Juan Martin Del Potro in the quarter-finals after the Argentine needed four match points and three hours to hold off Swiss Stanislas Wawrinka 4-6, 6-4, 6-4. The pair had played just over a week ago in Rome, with the Argentine earning his first victory after two losses in the series. It was windy but not swirling like at Indian Wells or Miami. I had a lot of chances in the first set but couldnt take them, added the Scotsman, who turns 22 on Friday and reached a career - and British - best of third in the world on Monday as he overhauled Djokovic. In the womens third round, top seed Dinara Safina defeated Lucie Safarova 6-0, 4-6, 6-3 while Serbian number four Jelena Jankovic reached the last eight beating Russian qualifier Elena Vesnina 6-2, 6-2.