With a semi-final place against Rafael Nadal up for grabs, Jo-Wilfried Tsonga and Mikhail Youzhny slug it out

Tsonga clinches the set with a brilliant backhand and Youzhny immediately has strapping on both ankles adjusted

Tsonga continues to call the shots and powers through the second set with some blistering serving and winners

And though the Frenchman's form dips in the third he still has enough in his locker to continue his amazing progress

World number one Justine Henin goes into her last-eight clash with Maria Sharapova with a 6-2 record over the Russian

Fifth seed Sharapova dictates proceedings from the outset with a succession of winners to take the opening set 6-4

Henin has no answer to her power and is blown away 6-0 in the second as her 32-match winning run comes to an end

It is Henin's first defeat since Wimbledon 2007 and Sharapova can look forward to a clash with Jelena Jankovic

Earlier, third seed Jankovic faces defending champion Serena Williams with a place in the semi-finals at stake

Jankovic comes into the match carrying thigh, knee and shoulder problems after some tough battles in earlier rounds

But it is Serena who is looking sluggish and feeling frustrated as Jankovic races to the first set, taking it 6-3

The cause of Williams' problems is a large blister on her big toe that soon needs treatment in the second set

But Jankovic has mobility problems of her own as her old thigh injury flares up again and she needs treatment too

Serena ups her game to leave Jankovic stretching that bad leg and the second set is in the balance

But Serena's serve lets her down again and she is soon back in trouble with Jankovic scenting victory

A relieved Jankovic completes her win and will play Maria Sharapova in the semi-finals on Thursday

Men's second seed Rafael Nadal is next in action, looking to reach the semi-finals in Melbourne for the first time

The Spaniard is up against Finland's Jarkko Nieminen, who at 24 is the lowest-ranked men's player left in the tournament

Nadal has to save two set-points in the first set but he is soon into his stride to open up a two-set lead over the Finn

Nadal does not let the pressure slip in the third set either, looking to overpower the Finn with his powerful groundstrokes

The match is fast slipping away from Nieminen, who struggles to hold up Nadal as he gains momentum

Nadal completes a one-sided victory in two hours and 19 minutes to reach his first semi-final in Melbourne