ROME: French Open champion Ana Ivanovic produced a fractured display as she was stunned by Poland's Agnieszka Radwanska 6-1, 3-6, 6-4 at the WTA Rome claycourt International on Wednesday.

Fifth seed Ivanovic had a disastrous start but she regrouped and seemed to be cruising into the quarter-finals at 4-0 up in the third set after a run of winning 10 out of 13 games.

But just as her first set play had been terribly inconsistent, so her demons returned and 10th seed Radwanska reeled off the final six games to clinch the match.

It was another remarkable turn-around for the Pole who had trailed 5-2 in a third set tie-break against France's Aravane Rezai late on Tuesday night before scraping into the third round.

Ivanovic, who has struggled with injury and form since her success at Roland Garros last June, has not won a tournament this year and reached only one final.

And this performance was typical of her erratic recent form, poor to begin with, then back in the swing before losing her touch again at the end.

Meanwhile reigning two-time champion Jelena Jankovic barely had to break sweat as she coasted into the quarter-finals when Kateryna Bondarenko retired with an illness.

Their third round match had been uncompetitive before the Ukrainian's retirement with third seed Jankovic charging to a 6-1, 1-0 lead before the end came.

It was a far cry from the Serbian's clash against Argentine clay specialist Gisela Dulko the previous day which lasted almost two hours.

World number four Jankovic will play seventh seed Svetlana Kuznetsova next after the Russian defeated home hope and 12th seed Flavia Pennetta 6-3, 3-6, 6-0.

Jankovic said she didn't want the match to finish that way but was looking forward to hitting the shops on her afternoon off.

"I would have loved to finish the match because I was playing pretty well in that first set," she said.

"I felt the ball really well and I had good timing so it was a good set, a good game for me.

"But, unfortunately my opponent was sick and there's nothing you can do about that.

"Maybe now I will do a little bit of shopping and that's it. I had an easy day today, unlike yesterday where I spent most of the day here.

"Already my mom has been going shopping. I kind of write a list of buy me this, buy me that so I don't know.

"I will go today for a little bit, not too much because I must save my energy for my match tomorrow."

In an early match sixth seed Victoria Azarenka of Belarus thrashed ninth seeded Dane Caroline Wozniacki 6-2, 6-2.