Aus Open Images: Roddick, Sharapova knocked out

Stanislas Wawrinka outclassed eighth seed Andy Roddick 6-3, 6-4, 6-4 on Sunday to set up an Australian Open quarter-final with close friend and fellow Swiss Roger Federer.

"Stan" -- as Beijing Olympic gold medal partner Federer fondly calls him -- out-aced American Roddick 24-9 as he ensured a first Grand Slam quarter-final between two Swiss men since the sport turned professional.

Wawrinka, seeded 19th but playing tennis 16-times Grand Slam champion Federer would have been proud of, caught Roddick cold under the Melbourne floodlights, breaking for 5-3 in the first set with a drilled backhand pass and never looked back.

Roddick was a step slower than his unshaven opponent, who had too many ideas and executed his shots superbly.

The contest ended after two hours and 22 minutes when Roddick sliced a weary backhand into the net to leave no Americans remaining in either singles draw.

Roger Federer toiled in the sun for a 6-3, 3-6, 6-3, 6-2 victory over Spain's Tommy Robredo on Sunday, earning the Swiss master a spot in the Australian Open quarter-finals.

Second seed Federer produced spells of jaw-dropping brilliance but also hit countless loose shots, mostly forehands, in a patchy performance on a sun-baked Rod Laver Arena.

The defending champion ripped through the first set in 32 minutes but a wild forehand gifted Robredo a break and another shanked shot the second set in a bizarre turnaround.

But Federer, looking to add to his record 16 Grand Slam titles, raised his game to take the third before closing out a tough match with a mid-court rocket Robredo could only dump into the net.

Novak Djokovic steamed into the last eight of the Australian Open with a 6-3, 6-4, 6-0 thrashing of Spaniard Nicolas Almagro on Sunday but fumed after being given a code violation for coaching during the match.

Djokovic was sanctioned by chair umpire Fergus Murphy early in the second set, but said he had only made eye contact with coach Marian Vajda in the stands.

"I don't think it was the right call, because I missed a forehand and then I turned to my coach as you always make as a player an eye contact with your team," said the world number three Djokovic, who faces a possible fine following a review.

"That's what I did. I didn't ask for any advice, you know, because they can't help too much. You've got to do what you got to do.

"What I'm saying is that even though I think it was the wrong call, if he thinks that it was right, he should have told me before giving me a warning.

"Just tell me, 'hey, maybe your coach is involved too much before the points, he's giving you signals'. I would say, 'yes, okay, sorry, no problem'."

Djokovic appeared in little need of coaching as he dominated the 14th seeded Almagro from the baseline. The 2008 champion faced just one break point in the first two sets then raced through the third in 28 minutes to seal an emphatic victory.

He fired 12 aces and 31 winners in the 106-minute contest and will meet Czech sixth seed Thomas Berdych in the quarter-finals.

The 23-year-old has been knocked out in the last eight for the last two years, losing to Andy Roddick in 2009 and Jo-Wilfried Tsonga last year.

"I'm hitting the ball well. Physically and mentally I'm fit and ready to win another match," said Djokovic, who came close to an elusive second Grand Slam at Flushing meadows, beating Roger Federer in the semi-finals but losing to Rafa Nadal in the final.

"If I go out with a white flag, you know, it's not the right attitude... Of course, I have big respect for (Federer) and Nadal and all the players, but I've won against all of them and I know how it feels like to play on the big stage."

Former world number one Maria Sharapova suffered a shock fourth round defeat at the Australian Open on Sunday, bundled out 6-2, 6-3 by bottom-wiggling German Andrea Petkovic.

Under pressure from the start, Sharapova committed 30 unforced errors in a performance which underlined her struggles since shoulder surgery in 2008, the year she won the last of her three Grand Slam singles titles in Melbourne

Bosnian-born Petkovic celebrated reaching the last eight of a major for the first time with an on-court jig.

"It started off as a bet with my coach," Petkovic told reporters of the cheeky dance of delight she peformed after her upset win.

"I'm very superstitious and since I started doing the dance I'm playing much better, so I'll try to keep it up," added the 23-year-old, who faces China's Li Na in the quarter-finals.

Squealing mightily on every shot, 14th seed Sharapova could do little right in the first set, spraying wild shots all over Rod Laver Arena.

The Russian showed a few signs of a possible fightback during the second set after going 2-0 down but the hole she had dug for herself was too big against a dangerous opponent.

She fended off two match points with a pair of rocket forehand returns but Petkovic completed victory in 79 minutes with a deep serve Sharapova could only push into the net.

"It definitely wasn't there," said a rueful Sharapova, who since winning here three years ago has reached just one Grand Slam quarter-final.

"Last year I was gone on Monday. I stayed here a little bit longer this year.

"But there are many things that didn't work today. I didn't get my first break point until it was a set and 5-1. That's not the type of tennis I want to be playing."

Iron-woman Francesca Schiavone survived the longest Grand Slam women's singles match in the professional era on Sunday, edging past Svetlana Kuznetsova after four hours 44 minutes to reach the Australian Open quarter-finals.

The 30-year-old Italian, who won last year's French Open in front of a fan club wearing T-shirts with the slogan "Schiavo Nothing Is Impossible", was on the brink of defeat at one point but fought off six match points before prevailing 4-6, 6-1, 16-14 on Hisense Arena.

An enthralling match began in bright sunshine and ended in the gloaming with both players exhausted and requiring visits from the trainer, however it was Schiavone who found the reserves of energy to break decisively at 14-14.

She sealed victory with a forehand volley at the end of a deciding set that lasted three hours -- a long way short of the more than eight hour monster contested by John Isner and Nicolas Mahut at Wimbledon last year but remarkable all the same.

"I hope one day to show this DVD to my son," said Schiavone, who became the second oldest player to win a maiden Grand Slam when she beat Australia's Samantha Stosur at Roland Garros last year.

"It's like every point is match point. You have to keep going. You know that physically you are tired, but the other one is too.

"Mentally it's the same ... We work every day to do this, to give the best when you really say, 'no, I can't do it.'

"But at the end you have something more, always."

Kuznetsova also saved two match points, the first with a baseline winner and the second with a sharp return that scorched her opponent's shoelaces, but could not grind down the the feisty Italian net-rusher.

"I just feel very empty. I don't know what to say," she said. "We both fought so hard the whole match, and the important moments she just played better.

"But statistically I also felt like I was the better player on the court ... Just very disappointing."

The match surpassed the four hour 19 minute slog between Czech Barbora Zahlavova-Strycova and Russia's Regina Kulikova at last year's Australian Open and fell one short of the 48-game record set by American Chanda Rubin and Spain's Arantxa Sanchex-Vicario, also at Melbourne Park.

China's Li Na powered past eighth seed Victoria Azarenka 6-3, 6-3 to book a spot in the quarter-finals of the Australian Open on Sunday.

Li, who lost to Serena Williams in last year's Melbourne semi-finals, had too much firepower for Azarenka, the ninth seed blowing her off court in 88 minutes.

The first Chinese player to reach the top 10 in 2010, Li wrapped up an easy win with another crunching backhand Azarenka wearily dumped into the net.

Li will play Germany's Andrea Petkovic in the last eight.

Caroline Wozniacki continued her news conference shenanigans at the Australian Open on Sunday, telling a tale of being scratched by a kangaroo and then later admitting on social networking website Twitter she had concocted the whole thing.

After making the quarter-finals with a 6-3, 6-4 victory over Latvia's Anastasija Sevastova, the Danish world number one told reporters she was attacked by a baby kangaroo at a wildlife park outside of Melbourne and had needed to get medical attention.

"I thought I was going to be nice and try to help it out because it was just lying there. I thought maybe it needed some help... I found out that I shouldn't do that," said Wozniacki, after pointing to some tape covering a 'wound' on her leg.

"Yeah, it scratched me pretty well.

"I went to the doctor. They cleaned it and everything. They wanted to do a few stitches. I said, 'there's no way you're going to do stitches'.

"It looked so cute. But once it started scratching me, I was a coward and I ran away."

Wozniacki later said on Twitter:

"Round 2 with the media:) hope you enjoyed my kangaroo story, hope you know i was just kidding:) see you on tuesday for round 3!"

The Dane ran her own media conference earlier this week after being fed up listening to questions about her status as a world number one without a Grand Slam title.

Wozniacki had trouble in the early exchanges against 46th-ranked Sevastova, who broke serve and marched to a 3-1 lead in the first set before the Dane settled and reeled off six games in a row.

Sevastova fought back to 4-4 after being a break down in the second set, but notched two unforced errors to hand it straight back and Wozniacki sealed the match after whipping a cross-court forehand winner.

Wozniacki, who has not dropped a set at the tournament, will next play French Open winner Francesca Schiavone or two-times Grand Slam champion Svetlana Kuznetsova.