Big guns all fire

Defending champion Rafael Nadal reached the Wimbledon last 16 on Saturday with a 7-6 (8/6), 7-6 (7/5), 6-0 win over Gilles Muller of Luxembourg.
Nadal will face Juan Martin del Potro of Argentina for a place in the quarterfinals. Former US Open champion del Potro set up the clash after he defeated Frenchman Gilles Simon 7-6 (10/8), 7-6 (7/5), 7-5.
Del Potro defeated Nadal in the US Open semifinals in 2009 en route to the first Grand Slam title of his career and could pose more problems for the Spaniard at the All England Club when they meet on Monday.
Reigning Wimbledon champion Nadal will be aware that Del Potro has won three of their eight encounters and, after missing most of last year with a wrist injury, the Argentine is finally fit and recapturing his best form.
However, it was a satisfying win for Nadal because he had lost to Muller in the second round at Wimbledon in 2005, the last time the two had faced each other.
Meanwhile, six-time champion Roger Federer sailed into the last 16, defeating David Nalbandian of Argentina in straight sets 6-4, 6-2, 6-4.
Federer now faces either Nicolas Almagro of Spain or Russian 18th seed Mikhail Youzhny in the next round for a place in the quarterfinals.
In the women's draw, defending champion Serena Williams eased past Russia's Maria Kirilenko 6-3, 6-2 to reach the last 16 in her most dominant display at the tournament so far.
Williams, the four-time winner, will face France's Marion Bartoli, the 2007 runner-up, for a place in the quarterfinals.
The American seventh seed had come into her 12th Wimbledon on the back of an 11-month injury lay-off caused by a foot injury followed by life-threatening blood clots on her lungs.
But after needing three sets to see off Aravane Rezai and Simona Halep in her first two matches, the 29-year-old looked back to her best on Court One on Saturday.
She fired down 10 aces and 32 winners past the out-classed 27th-seeded Kirilenko, wrapping up victory on her third match point.
Williams needs to make the semifinals to ensure that she doesn't drop out of the world's top 100.
Former champion Maria Sharapova eased into the last 16, thriving on the same Court Two which was so bitterly criticised by title rival Serena Williams.
Fifth seed Sharapova, the 2004 champion, saw off Klara Zakopalova of the Czech Republic 6-2, 6-3 and will tackle China's Peng Shuai for a place in the quarterfinals.
"I haven't been past the fourth round for a few years so I am happy to get where I am. I hope to go one step further and even more," said Sharapova.
Peng, the only Chinese player left in the draw after the second round exits of French Open winner Li Na and Zheng Jie, reached the fourth round for the first time with a 6-2, 7-6 (7/5) win over unseeded Hungarian Melinda Czink.
Top seed Caroline Wozniacki was as untroubled as Sharapova with the Danish world number one reaching the fourth round for the third successive year with a 6-3, 6-2 win over Australia's Jarmila Gajdosova on Centre Court.
Wozniacki, still searching for a first Grand Slam title, will next face Slovakian 24th seed Dominika Cibulkova who booked her last 16 place with a 6-4, 1-6, 6-3 win against German 16th seed Julia Goerges.