Cathy Freeman's unbeaten reign of 1,712 days and 24 races ended as her heir apparent Jana Pittman trounced her over 400 metres in the A-Series athletics meet in Sydney.

Not since Oslo in 1998 has Freeman lost over her Sydney Olympic gold medal distance.

The 20-year-old Pittman went out hard from the blocks, shedding runners to hit a 20 metre lead over her childhood idol.

Freeman's kick never eventuated and the Manchester Commonwealth Games 400m hurdle gold medallist pulled away to win in a super-fast of 50.43, more than a second ahead of Freeman (51.81), with Rosemary Hayward third in 53.07.

Pittman, 20, clocked an A qualifying time for the Paris world championships in August.

Running her first flat 400 metre race in two years, Pittman said the experience was like an Olympics but she didn't feel overawed by the diminutive champion.

"I'm an animal, I love what I do and I want to win," Pittman said.

"I was pretty pleased I coped with it mentally - I was very nervous. At the start line I thought 'I have no idea what is going to happen here'. I knew it would come down to who had the biggest guts in the end."

Freeman, who admitted she was only still at 85 per cent fitness, said the loss showed just how much more work she had ahead of her with the world championships.

"I'm impressed - good running by Jana. It tells me how much more work I have to do," the 30-year-old said.

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