Nadal rising to toughest Wimbledon challenge

World number one Rafael Nadal believes winning Wimbledon will be harder than ever this year with all of his closest rivals fit and firing on all cylinders.

Spain's Rafael Nadal serves to Luxembourg's Gilles Muller during the men's single at the Wimbledon Tennis Championships at the All England Tennis Club in southwest London. The defending champion reached the Wimbledon last 16 with a 7-6 (8/6), 7-6 (7/5), 6-0 win over Muller.

Nadal booked his place in the second week of Wimbledon fortnight here Saturday after completing a 7-6 (8/6), 7-6 (7/5), 6-0 third round win over Luxembourg's Gilles Muller.
Reigning champion Nadal, who will face Juan Martin Del Potro in the last 16, was in imperious form against Muller, totting up a miserly three unforced errors as he sailed into the fourth round.
But Nadal is only too aware of the challenges which lurk in the later stages of the tournament, where six-time champion Roger Federer, Serbian second-seed Novak Djokovic and in-form world number four Andy Murray remain.
Nadal said the depth of talent in the men's draw made this year's Wimbledon one of the most unpredictable ever.
"You never know what's going on," Nadal said. "It seems like the best players are playing well. I don't know if I'm gonna win next round, so probably the rest of the players think the same.
"Every day is different. Every day anything can happen. Novak, Roger, Andy are playing well. But the matches are not easy to win. So the matches are close all the time. It's difficult to predict something."
Nadal, who is seeded to face Murray in the semi-finals, must first negotiate a way past Del Potro on Monday, the Argentinian 24th seed who accounted for 15th seed Gilles Simon in the third round.
"He's a very, very tough opponent. One of the best players in the world. He had an important injury last year," said Nadal, who believes Del Potro's ranking of 21 does not reflect his talent.
"His ranking for sure is much better than what the ranking says today. His level is much better than what the ranking says today.
"In my opinion, he's top five level normally, if we talk about level. When he's healthy, he must be in the top five of the ranking normally. So will be a very tough opponent for me."
Against Muller, who had beaten Nadal here in 2005, the Spanish top seed's class told in the tie-breaks.
Nadal had taken the first set tie-break on Friday night before rain halted the match, and Saturday's second set followed almost an identical pattern.
Neither player showed any sign of vulnerability on serve but Nadal forged into a two-set lead when a Muller backhand into the net gave him a set point at 6/5 in the tie-break which his rival duly converted.
The tie-break loss shattered Muller's resolve and Nadal scored three consecutive breaks and held to wrap up the third set 6-0 in only 31 minutes.