Sunday was a day of upsets at the Australian Open. First we saw the number two seed Amelie Mauresmo suffer a shock defeat at the hands of world number 70, Lucie Safarova. Next came the defeat of number three seed Svetlana Kuznetsova by Israel's Shahar Peer and we also said good bye to the number nine seed Dinara Safina who lost to China's Li Na.

I look forward with interest to see how the players that have so far achieved career best results cope with the pressure involved with playing at the business end of the tournament. Peer is the first Israeli woman to make a Grand Slam quarter final and Sararova is also there for the first time.

Safarova is the one with the most to gain as she will make a big leap up the rankings because she is so far is guaranteed 250 ranking points. Without progressing further, she will jump to around 30 in the world. If she can overcome Nicole Vaidisova in the quarter finals she could be looking at a top-25 ranking. 

It is always tough to follow up a win over a top 10 ranked player and quite often players fall in a heap in the next match but Sararova can show the tennis world she has what it takes to be a star of the future by playing well and defeating Vaidisova.

Peer is also in new territory, as no Israeli woman. She is already ranked in the top 20 but if she is able to advance -- for which she will have to overcome Serena Williams -- she can make a push towards the world's top ten. Can she handle the pressure of a Grand Slam quarter final? She will need to be at her best mentally and physically to overcome a rejuevenated Serena Williams who also has something to prove.

Of the other players still in the tournament are Maria Sharapova who is now the clear favourite for the title. After her first-round escape, Sharapova has played strongly to win her next  two matches with the ease expected of the top seed. In her next match she takes on former top-ten player Vera Zvonareva. Due to the heat not being a factor I favour Sharapova to win.

Kim Clijsters plays Daniela Hantuchova for a quarter final spot. Clijsters is probably the toughest obstacle in the way of Sharapova's title ambitions. The pair could meet in the semis if they both progress as planned, which I expect will happen. I look forward to this blockbuster semi final match.

Other players in this quarter of the draw are Li Na, Martina Hingis, Anna Chakvetadze and Patty Schnyder. I don't see them as a threat to the top two remaining seeds.

In the bottom half of the draw I think Williams will overcome Peer and I think the pressure will be too much for Safarova to handle, so I am tipping Vaidisova to make her way to a semi final against Williams.