The fourth round of the Australian Open tennis tournament, currently being held in Melbourne, saw two of the top three women players in the world knocked out of the running.

In two matches between four Russian players the world number two, Dinara Safina, was beaten by Maria Kirilenko. Svetlana Kuznetsova, currently ranked third, was beaten by Nadia Petrova. Petrova will play Belgium’s Justine Henin in the quarter finals. Henin, who recently returned to the tennis circuit after a two-year absence, beat her fellow countrywoman Yanina Wickmayer in three sets.

In the men’s competitions, defending Spanish champion Rafael Nadal beat Croatia’s Ivo Karlovic in four sets to go through to the quarter finals, where he will play Scotland’s Andy Murray. Argentina’s Juan del Potro, who won the 2009 US Open, lost to Croatia’s Martin Cilic in a marathon struggle that lasted almost five hours.

Photo of Justine Henin (left) from Wikimedia Commons

Photo of Maria Kirilenko (centre) by Daryl Sim (flickr)

Photo of Nadia Petrova (right) by franz88 (flickr)