Serena crushes Stosur

Serena Williams produced a serving masterclass to end local interest in the women's draw with a 6-4, 6-2 demolition of Samantha Stosur in the fourth round of the Australian Open on Monday.

The defending champion gave up just two points on serve in the first set and seven in total against the 13th-ranked Australian, who had beaten the American world number one the last time the pair met at Stanford last year.

The top seed also put pressure on Stosur's serve when she needed to, breaking once in the first set and twice in the second to run out an easy winner in a little over an hour.

Williams will now meet either Victoria Azarenka or Vera Zvonareva in the quarter-finals.

Former champion Novak Djokovic charged into the quarter-finals of the Australian Open on Monday, thrashing Poland's Lukasz Kubot 6-1, 6-2, 7-5.

Kubot, who was given a walkover in the previous round after Russia's Mikhail Youzhny pulled out injured, was completely outclassed by Djokovic, who committed only 17 unforced errors in wrapping up the match in less than two hours.

The 86th-ranked Pole offered belated resistance in the third set, but Djokovic broke him at 5-5, then sealed victory on the second of three match points with an imperious forehand winner.

The third-ranked Serbian will meet either France's Jo-Wilfried Tsonga, who he beat to win the 2008 title at Melbourne Park, or Spain's Nicolas Almagro for a semi-final place.

Venus Williams continued her domination of Francesca Schiavone on Monday, coming back from a set down to defeat the Italian 3-6, 6-2, 6-1 and reach the quarter-finals of the Australian Open.

Seventeenth seed Schiavone, who had never beaten Williams in five previous matches, looked set to break the trend after taking the first set and an early break in the second.

Williams broke back immediately to steal the momentum, however, and then steamrolled the Italian in the last set with confident net-play.

"She played really well in the first set. I have to give her credit. She just played really aggressively," Williams told reporters. "You know, she was making her shots, doing everything she needed to do to win the match.

"But, obviously it takes a lot to close out a match, especially on an important match like that one.

"I was able just to get some footing back in and start to execute the way I wanted to."

Nikolay Davydenko continued his run at the Australian Open with a tense 6-2, 7-5, 4-6, 6-7, 6-3 fourth round victory over ninth seed Fernando Verdasco on Monday.

The Russian sixth seed, the form player on the men's tour over the past six months, had not lost a set coming into the match but the Spaniard showed in the third and fourth sets that he was vulnerable.

Verdasco, who made the Australian Open semi-finals last year, sent the match to a deciding set, however, the Russian achieved the crucial break in the sixth game and clinched victory when the Spaniard's return crashed into the net.

He will next face either world number one Roger Federer or Australia's Lleyton Hewitt in the quarter-finals.

Caroline Wozniacki's dramatic rise through women's tennis was halted on Monday when Chinese 16th seed Li Na dumped her out of the fourth round of the Australian Open 6-4, 6-3.

The 19-year-old Dane, who stormed into the world's top five on the back of three titles and a US Open final last year, had declared herself free of the big-match nerves that plague young players after thrashing Israel's Shahar Peer in the third round.

Against hard-hitting Li, however, the bravado disappeared all too quickly when challenged in the first set, and remained absent when the Chinese offered a number of opportunities to level in the second.

"I had my chances especially in the first set leading. I had my chance (to go to) 5-2 and didn't take it," a gloomy Wozniacki, who advanced to the fourth round without conceding a set, told reporters.

"I tried to hang in there but it just didn't go my way today."

The loss was her second in two weeks to the dangerous Li, who has proved her giant-killing credentials with wins over three top-10 players last year.

"Against her you need to just play on your highest level the whole match through and keep concentrated and keep a lot of balls in play," Wozniacki said.

The Dane played in some discomfort and had her leg strapped by a trainer while trailing 3-1 in the second, but said it "didn't affect the score at the end."

Having enjoyed the packed crowds of a grand slam centre court far quicker than most players her age, Wozniacki now faces a lonelier, more introspective spell on the practice court.