Nothing slowing down Radwanska

MELBOURNE, Australia -- Memo to Chinese No. 6 seed Li Na: Might want to arrange for Aussie Open quarterfinal opponent Agnieszka Radwanska to get caught in a traffic jam without her smartphone.

The No. 4 seed from Poland has won 13 straight matches and two titles (in Auckland and Sydney) this season and looks unflappable. But she admitted during a postmatch interview following her 6-2, 6-4 fourth-round win over Serbia's Ana Ivanovic that there are a couple of things that get under her skin: slow drivers and bad Internet service.

Radwanska has steered efficiently through the draw, displaying her usual shot-making versatility and using the whole court with a purring confidence. But even by her recent standards, her masterful defeat of an off-balance Ivanovic was a model performance. Radwanska committed only four errors (to Ivanovic's 34) during the entire match.

"I think no one is unstoppable, to be honest," Radwanska said. "This is sport -- this is tennis. But like I'm playing, it's just great feeling I can really play my best tennis from the beginning of the year. It's been a great three weeks so far."

Spain's David Ferrer is a mathematical member of the big four here in the continued absence of countryman Rafael Nadal, but he would have none of that number-crunching Sunday after wearing out a less-than-full-gas Kei Nishikori 6-2, 6-1, 6-4 in their fourth-round match. Ferrer played what he called "one of the best matches on my career in [the] Australian Open" but demurred when asked about his status.

"Now I want to be focus with my next match. Is very difficult for to win a Grand Slam because there are the top four. In this moment, the last three or four years, they are better than the other players," Ferrer said, as if peering at the big boys through a knothole in a fence. "But, you know, I am not thinking about if I have the chance to win a Grand Slam. I am only focus with every match I will play."

The 16th-seeded Nishikori repeatedly grasped his taped left knee in apparent discomfort during the match, but didn't want to blame that entirely for the loss.

"It's more like he play well today," Nishikori said. "You know, you have to be really 100 percent against these guys … it's not easy when you have something. You know, I was worrying a little bit, but no, it was OK."

Ferrer's quarterfinal will be an all-Spanish affair after No. 10 seed Nicolas Almagro advanced in a match shortened to 6-2, 5-1 by the retirement of Serbian No. 8 seed Janko Tipsarevic because of a foot injury incurred while changing directions on the run in the first set.

France's Gilles Simon, completely spent and in need of a massage rather than an interview after cramping badly through much of his marathon late-night 6-4, 6-4, 4-6, 1-6, 8-6 win over Gael Monfils in the third round, spoke to reporters Sunday afternoon.

"I felt I played the end of the match like in a dream, like I was not even on the court," said the 14th-seeded Simon, who was driven back to the main tennis complex from Hisense Arena and could barely shuffle stiff-legged down a corridor to the locker room even with assistance. "I was just hitting the ball, trying to run, trying to catch it, and not thinking anymore."

Both men were aching (Simon is also nursing an elbow injury and Monfils tender knees) and the match featured many long rallies in which both players would lay in wait for each other rather than taking the initiative. Fans were entranced by one 71-shot exchange that lasted close to two full minutes. Simon said he wasn't counting, and frankly could have done without that much drama.

"We always play some long points with Gael," he said of a match in which the players made a lot of circus shots but also at times were reduced to strolling rather than running.

Simon takes on No. 3 seed Andy Murray of Great Britain in a match mercifully scheduled for late Monday afternoon Australia time.