Former world number one Ana Ivanovic blamed an injury setback for her shock early exit from the Australian Open on Tuesday.

Ivanovic, the 2008 French Open winner and Australian Open runner-up was beaten 3-6 6-4 10-8 by the 49th-ranked Russian Makarova on Tuesday night.

Ivanovic was forced to withdraw from this month's Hopman Cup mixed-teams tournament in Perth after suffering a stomach injury. The 23-year-old Serbian starlet said an abdominal strain had hampered her preparation.

"I was really unlucky, for the last 10 days I couldn't push hard in practice because of my abdominal strain," she said.

"What really I think got to me in the end was fitness, you know, just not being able to stay with her in a longer rallies. That was really disappointing."

"I really only had Sunday and Monday that I could push a little bit more and could actually serve."

"I think that at the end got to me. Energy-wise I felt good, but it was just that few little extra steps that were lacking."

The loss will not discourage Ivanovic from her goal of returning to the top 10. Ivanovic was Roland Garros champion in 2008, the same year she was runner-up in the Australian Open. She was runner-up at Roland Garros in 2007. Ivanovic was ranked world No 1 in June 2008.

"I'm certain about it. This match, this loss, is tough. But I gave my best. That's all I can ask for," she said.

"You know, today she was better. All credit to her. I certainly still believe I can get back to top 10, and I believe I can do it in this year."

Meanwhile, Makarova said it was the biggest win of her career, having been beaten by Ivanovic in straight sets at last year's US Open in their only previous meeting.