Rafael Nadal of Spain celebrates defeating Juan Martin Del Potro of Argentina at the Wimbledon tennis championships in London, June 27, 2011. [Photo/Agencies]

The Manic Monday carnage in women's top seeds did not extend to the men's singles although defending champion Nadal suffered a major injury scare during a scintillating late evening win over Juan Martin del Potro in front of a captivated Centre Court crowd.

Nadal won 7-6 3-6 7-6 6-4 while six-times champion Roger Federer lost his first set of the tournament in beating Russian Mikhail Youzhny as home flag bearer Andy Murray and world number two Novak Djokovic sauntered through in straight sets.

Nadal needed lengthy treatment on a mystery foot complaint at 6-6 in the first set and admitted he thought his title defence was over.

"It felt terrible at 6-5," Nadal, who extended his Wimbledon winning streak to 18 matches, told reporters. "It felt like I had broken my foot, I didn't know if I could continue playing." The 25-year-old will have an MRI scan to assess the damage.

Australian Bernard Tomic continued his memorable run, the 18-year-old thrashing Belgium's Xavier Malisse to become the youngest player to reach the men's quarter-finals since 1986.

With all eight men's and women's last-16 matches slated on the schedule the All England Club was abuzz from the moments the gates swung open on a stifling morning.

Andy Murray of Britain bows to Catherine Duchess of Cambridge and Prince William in the Royal Box after defeating Richard Gasquet of France at the Wimbledon tennis championships in ,June 27, 2011. [Photo/Agencies]

The recently married Prince William and Duchess of Cambridge did have the best seats in the house and would have given their seal of approval to the world No.4s most impressive display this year as he dismantled Gasquet in three sets.

Next in Murray's firing line as he aims to become the first British man to win Wimbledon since 1936 is Spanish left-hander Feliciano Lopez who hit back from two sets down to beat Poland's Lukasz Kubot.

Djokovic, who can replace Nadal as world number one by reaching the final, had a relatively stress-free workout against Michael Eldora, dropping just nine games en route to an intriguing quarter-final with young gun Topic.

Third seed Federer had a jolt when he lost an opening set tie break to Youzhny but was majestic thereafter, gliding through the next three sets 6-3 6-3 6-3.

Roger Federer of Switzerland waves after defeating Mikhail Youzhny of Russia at the Wimbledon tennis championships in London, June 27, 2011. [Photo/Agencies]