Intro:

Ana Ivanovic, 27, beat world number one Serena Williams, 33, in the Australian Open fourth round on Sunday to cause one of the shocks of the tournament.

Script:

Ana Ivanovic caused one of the upsets of this year's Australian Open by beating world number one Serena Williams in the fourth round on Sunday.

The match began promisingly for the five time champion who won the first set but Ivanovic fought back to level in the second.

Williams then saved break and match point in the third set.

Ivanovic had failed to beat the American in the last four attempts but she served out a victory which she described as 'amazing':

SOUNDBITE: (English) Ana Ivanovic (on how the win over Serena Williams felt):
"That's a funny question (laughter.) It's amazing. I mean, this victory means so much to me. And, you know, I worked so hard and all the hard work, you know, it's paying off. Like I said, you know, I had very tough fourth round matches in a Grand Slam, and this was probably the toughest. I just went out there to play. I had nothing to lose, as well. I just kept swinging. Even when I made errors I really, you know, believed in it. So to have that victory, you know, it's amazing. We all know what kind of champion she (Williams) is. And when we were starting the match and they were talking about all her Grand Slam titles, it was quite impressive (smiling)."

Ivanovic will play in her first quarter-final of a grand slam in two years against Canadian Eugenie Bouchard.