World champion sprinter Black Caviar has produced a gallop so fast her trainer has described it as "scary" as she prepares to stretch her unbeaten record to 25 on Saturday.

"That's almost as fast as she's ever gone here at Caulfield," said trainer Peter Moody after the mare worked on the course proper on Monday.

"You don't want to know what time she ran. It'll scare you."

The gallop provided the perfect answer to questions raised by a rival trainer over the legitimacy of the super mare's recent Melbourne form.

Black Caviar attempts to pass her latest milestone in Saturday's TJ Smith Stakes at Randwick where her opponents will include the Joe Pride-trained Rain Affair.

Pride questioned the merit of Black Caviar's recent Lightning Stakes and William Reid wins, suggesting the Melbourne races were run in lanes to protect the super mare's record.

Pride threw down the challenge in Sydney over the weekend, saying Saturday's Group One sprint "won't just be a trot and canter like some races Black Caviar has been in".

"We don't race in lanes in Sydney. We will be going out there to beat her," Pride said.

Moody labelled the comments as "ridiculous".

"It's amazing how fast horses like Rain Affair all look fast until they've been up against her," he said.

"We've always been very respectful of our opposition because every field she's raced in has had Group One winners in it."

Moody cited the example of Magic Millions winner Karuta Queen, who has twice chased Black Caviar home.

"Karuta Queen was leading the best in Sydney by four lengths and she comes down hear and Black Caviar's sitting on her tail going half pace," he said.

The light-hearted sniping aside, Moody expressed absolute delight at Black Caviar's health and condition after Monday's gallop which was run in the Sydney direction, starting at the winning post and finishing at the 800m pole.

"I'm just amazed that this stage of her career, as a six-year-old, she's as sound as she's been for three or four years," Moody said.

"I'm not suggesting she's going better, but she's going as good as she ever has. It's quite remarkable."

Moody said Black Caviar been troubled by various injuries and niggles since she was a three-year-old, but since having a long spell after returning from England last year she's has been almost totally rejuvenated.

"She's the complete package now, stupid as it sounds," he said.

"She could work like that when she was a three-year-old, but it was rushed, not like today.

With the passing of his exuberance, Moody revealed that Black Caviar had dashed over the final 400m of her 800m gallop in under 22 seconds, an effort that left him "ecstatic".