A display of violent hitting from Robin Soderling on Saturday showed why it is always unwise to ignore a Swede at the business end of Wimbledon as Serena Williams gave herself a 'must do better' report as she eased into round four.

Another warm day in south west London promises much with world number one and 2008 champion Rafa Nadal making his bid for fourth-round berth while 'Andy-monium' reaches fever pitch again when home hope Andy Murray takes to Centre Court.

Until 1922 the reigning singles champions at the All England Club were granted byes to the final the following year and at times against Dominika Cibulkova on Saturday it seemed a policy worth reviving given Serena' complete dominance and lack of competitive challenge.

The 28-year-old three-time champion bludgeoned her way through the opening set in just 18 minutes, the third straight match she has won the first without losing a game, but the Slovak finally struck some kind of form to at least spare any further blushes.

"I served well in the second set but that was about all I did well. I have to play better than what I did today," said Williams, sporting a strawberries and cream dress on her return to Centre Court.

The victory set up a potential repeat of the 2004 final against Maria Sharapova should the 16th seed come through later on Saturday against Czech Barbora Zahlavova Strycova.

Victoria Azarenka, the 14th seed from Belarus, was sent packing 7-5, 6-0 by Czech Petra Kvitova as Chinese ninth seed Li Na reached the last 16 for the second time in three years with a 6-1, 6-3 win over Australia's Anastasia Rodionova.

Some of the leading men's seeds will have been anxiously checking the draw earlier this week to see just where they might run into Soderling, who is becoming a real challenger for the title on the skidding lawns.

Soderling battered 15 aces in a bulldozing two-hour performance against Brazilian 25th seed Thomaz Bellucci on Court One, winning 6-4, 6-2, 7-5.

The Swede, a player transformed since two appearances in the French Open final, alters his game little for grass with big-swinging forehands and angled backhands that left Bellucci pinned against the back wall for much of their third-round battle.

Not since Stefan Edberg in 1990 has a Swede graced the final here but Nadal and Murray will certainly be wary of his presence in their half of the draw.

"I played well today and despite it only being three sets it was tough," said Soderling, one of only three men yet to drop a set in the tournament.

To reach the quarters for the first time Soderling must next beat David Ferrer after the Spanish ninth seed came from 4-2 down in the fifth to beat Frenchman Jeremy Chardy.

Third seed Caroline Wozniacki overcame a battling performance from fellow teenager Anastasia Pavlyuchenkova to beat the Russian 7-5, 6-4 and reach the fourth round.

The 19-year-old Dane, who also reached the same stage of the tournament last year before bowing out, was never at her best but eventually outslugged her younger rival from the baseline.

Pavlyuchenkova, 18, had her moments, breaking early in the second set but could not sustain the momentum as she lost to Wozniacki for the third time this year.

Unseeded Czech Petra Kvitova, who knocked out 14th seed Victoria Azarenka on Saturday, awaits Wozniacki on Monday.

World number one Rafael Nadal survived to reach the second week of Wimbledon after again being pushed to the limit to overcome inspired German Philipp Petzschner 6-4, 4-6, 6-7, 6-2, 6-3 on Saturday.

The 2008 champion had to battle back from two sets to one down in the previous round against Robin Haase and was forced to do so again as fans packed on to a sun-baked Centre Court sensed the tournament's first major shock.

Although Nadal eventually came through, doubts over his fitness were raised for the second week of the tournament with the Spaniard receiving frequent visits from the trainer for treatment on his arm and legs in the three hours and 45 minutes contest.

Nadal, who also received an official warning by the match umpire for coaching by his uncle and coach Toni Nadal sat in the players' box, finally broke Petzschner's spirit when he broke to lead 5-3 in the decider, before serving out to secure a fourth round clash with Frenchman Paul-Henri Mathieu.

Andy Murray's Wimbledon challenge gathered pace as he cruised past Frenchman Gilles Simon 6-1, 6-4, 6-4 and into the last 16 on Saturday.

Centre Court was already in shade before the world number four began but he wasted no time against the 26th seed, producing a clinical display.

Murray, hoping to become the first British man to win the singles here since 1936, overwhelmed Simon in a 23-minute first and although he was made to work harder there on in he always had his opponent under control.

An ace clinched his third straight sets victory and the 23-year-old will head into the second week full of confidence.