Ivanovic pulls off the shock of the tournament so far

Ana Ivanovic has undoubtedly shocked tennis fans around the world as she dumped Serena Williams out of the Australian Open.

Ivanovic came back from a set down to win 4-6 6-3 6-3- her first ever win over Williams in five attempts.

Prior to the match there had been reports that Serena was suffering from a back injury, this turned out to be true.

"I almost pulled out. I'm such a competitor, I probably should have," said the world number one.

"I don't want to blame anything. I feel like Ana deserves all the credit. I feel she played unbelievable today. I think she went for her shots."

Ana Ivanovic was once world number one and 2008 French Open champion, but since that career high she has reached just one major quarter-final at the 2012 US Open. 

The Serbs record against Williams isn't great, however optimism started to grow as Ivanovic was able to unsettle the American's serve.

Ivanovic was given four break points in the opening set, converting one, but was broken twice as Williams edged it. 

After that it was all change in Melbourne, Ivanovic was now in control. Her serve was holding up well while Williams appeared to struggle with her movement, and she did not face another break point. 

Although Williams managed to serve two match points, it was Ivanovic who closed it nervelessly with a love hold after one hour and 56 minutes.

Ivanovic will play 19-year-old Eugenie Bouchard in the quarter-finals on Tuesday.