When rare Melbourne drizzle put a dampener on the start of day five, it was left to Serena Williams and Roger Federer to ignite the Australian Open on Friday.

Unseeded this year after a string of injuries dogged her 2006 season, two-times former champion Williams looked dead and buried against fifth seed Nadia Petrova at a set and 5-4 down with the Russian serving for a place in round four.

But Serena dug deep and shattered Petrova's resolve with a 1-6, 7-5, 6-3 victory and a place in the last 16 against red-hot Serb Jelena Jankovic.

Though delighted with her comeback victory -- her third in the tournament against the luckless Muscovite -- Williams seemed more concerned her father was watching her efforts.

She was seen mouthing 'Hi Dad, call me' to the cameras as she celebrated her win and revealed to reporters afterwards that it was a plea to her mentor Richard to get in touch.

"I'm trying to reach my dad, I haven't been able to reach him for a few days. I know he's watching so maybe he'll call me. Whenever I call him my number doesn't come up. It's so frustrating."

FEDERER FRUSTRATION

Federer inflicted technical frustrations of a different sort on Mikhail Youzhny, using the Hawk-eye system he had earlier in the week derided as 'nonsense' to help him pass the Russian 25th seed in straight sets.

At set point in the opener, a Federer serve was called out but the Swiss referred the call to the instant replay technology and the decision was overruled, giving him a 6-3 filip.

A string of disputed calls in the third set left the Swiss bereft of challenges and another decision irked him in the closing stages of a tense tiebreak, but he went to on to seal a fourth-round tie with Novak Djokovic 6-3, 6-3, 7-6.

"I wish I had none (challenges) all the time, nothing has changed," an unforgiving Federer blasted after his eighth straight win over the Russian.

Serb prodigy Djokovic, the 14th seed, dropped his first set of the week when coming through in four against Thailand's Danai Udomchoke, the last Asian representative in the men's draw.

"Federer is a big challenge," the 19-year-old said after his 6-3, 6-4, 5-7, 6-1 victory.

"Everyone knows his game but he's so perfect and makes everything look so easy. But if I go on court with a white flag then what am I doing here?"

Home hopes took another blow in heartbreaking fashion when veteran Wayne Arthurs was forced to bow out of his third-round match after three games with an ankle injury picked up during the warm-up with American Mardy Fish.

FANS CHOKED

Margaret Court Arena was packed in the hope the 35-year-old might stage one last hurrah before heading into retirement, but the fans and the popular Australian were left choked as it became clear Arthurs could not support his right leg.

He gave it three games of painfully restricted movement before throwing in the towel.

"It's a tough way to end it all," Fish told reporters.

Defending women's champion Amelie Mauresmo happily strolled into a last-16 place against unseeded Czech Lucie Safarova after a 6-3 6-1 win over another Czech, world number 83 Eva Birnerova.

Third seed Svetlana Kuznetsova bustled her way through at the expense of fellow Russian and 26th seed Maria Kirilenko 6-1, 6-4.

While local gardeners and farmers danced with delight as the rain fell on drought-blighted Victoria, organisers cursed as a four-hour rain delay hit the uncovered outside courts.

When the rain did stop, Jankovic wasted little time in confirming her place against Williams.

The 11th seed, already a winner this year in Auckland, came through against Victoria Azarenka of Belarus 6-3, 6-4.