It was another good day for the top-three as all of Rafael Nadal, Novak Djokovic and Roger Federer progressed into the last-eights of the Madrid Open.

World number one Nadal perhaps had the easiest encounter as his opponent, Argentine Juan Martin Del Potro, pulled out of the match with a hip injury.

The Spaniard will face Frenchman Michael Llodra next after he battled past Spain's Daniel Gimeno-Traver 1-6 6-4 7-6 (7-4).

Number two Novak Djokovic continued his irrepressible form, extending his winning streak to 29 matches after beating Guillermo Garcia-Lopez. The win saw him equal Ivan Lendl's record, set in 1986. In the elite list, Djokovic now only has Bjorn Borg (33 match winning-streak set in 1980) and John McEnroe (42 match winning-streak set in 1984) above him.

The Serb displayed exactly why he equaled Lendl's record against Garcia-Lopez. He was 4-0 up in the first set, which he took in 23 minutes before going on to secure a 6-1 6-2 victory in a mere 51 minutes.

However, with all the cool of a Serb, he insisted, yet again, that the winning-streak was the least of his priorities.

I am very flattered to be able to have the same amount of wins as this tennis legend but it's not something I think about. It's the least of my priorities. I just want to keep on winning and that's what it's all about.

I know I'm playing great now but there is always something you can improve on - you can never be perfect. I'm winning service games comfortably. That's something I'm happy about and an encouraging fact for upcoming matches, especially on clay.

Djokovic will now face sixth seed David Ferrer who held off Sergiy Stakhovsky 6-3 7-6 (7-3).

Elsewhere, World number three Federer who was given a tough time my Feliciano Lopez in the second round, had a comfortable match, racing into a 3-0 lead within nine minutes against Belgium's Xavier Malisse.

However, the Belgian, being unpredictable, battled back but was unable to stop Federer from taking the set 6-4. Malisse had to defend three break points in the opening game of the next set, but Federer broke him in the sixth game before taking the match 6-4 6-3 in an hour and 10 minutes.

The win set up an enthralling quarter final contest against Sweden's Robin Soderling who saw off Frenchman Jo-Wilfried Tsonga 7-6 (8-6) 7-5.

It wasn't a good day for British number one Andy Murray though, as he was beaten 6-4 6-2 by Brazilian world number 36 Thomaz Bellucci.