Kelso will decide on Monday whether to pay late entry fee and take on Habibi at Ellerslie.

New Zealand's two leading fillies are on a surprise collision course in the New Zealand Derby - and it will cost one of them $22,500 just for a shot at the classic.

Exceptional filly Fix is set to join long-time favourite Habibi in the TV3-sponsored Derby at Ellerslie on March 2, with her connections likely to pay the late entry fee.

While a final decision will not be made until after the Avondale Guineas at Ellerslie on Sunday, co-trainer Ken Kelso says the Derby is now Fix's main focus.

She was originally to be set for the New Zealand Oaks at Trentham on March 16, victory in which would guarantee her the NZB Filly of the Year title.


But her connections have now decided on a shot at the biggest classic of them all, providing a clash of the two fillies who dominated the three-year-old races at the Ellerslie Christmas carnival.

"The Derby is a very much a target now," said Kelso.

"And if she goes there it will be instead of the Oaks. She won't do both."

Kelso says the change of plan is influenced by several factors.

"We think it might simply be what is best for her, to start with," explains Kelso.

"She is unbeaten in three starts at Ellerslie and we are also not entirely sure she is a true 2400m horse.

"But 2400m at Ellerslie is not always the extreme staying test for a 3-year-old that 2400m of the Oaks at Trentham is."

Fix heading for Ellerslie could boost a super strong fillies' presence in the classic, which was won by wonder filly Silent Achiever last season.

And Fix and Habibi share something in common apart from their rampant recent form - jockey, Vinnie Colgan.

"That is another issue going forward because Vinnie is committed to Habibi," said Kelso.

"Finding the right jockey at 54.5kg provides its own challenges."

Habibi will be the headline act in this Sunday's Avondale Guineas at Ellerslie and Kelso will be watching with great interest.

"And, of course, we will wait until after the Guineas before we make our final decision on the Derby," he says.

"And that is not because of Habibi. I will just be interested to see the race and what comes out of it."

So when will the final decision on Fix setting up a clash of the super fillies in the Derby be made?

"By next Monday I should have more idea about whether we are definitely going and who the rider might be." Fix and Habibi could also be joined in the Derby by Soriano, who is running second in the Filly of the Year contest.

If she was going to concentrate solely on the Oaks she would appear to have the upper hand in the title chase, but if she races in the Derby, Kelso and Fix's connections might feel they can miss the Oaks and hope for a tired Soriano to turn up at Trentham.

Habibi remains the $3.50 favourite for the Derby, ahead of Waikato Guineas winner Castlzeberg at $5.

Because Fix is not nominated for the Derby she is not actually in the New Zealand TAB futures market, so punters wanting to back her will have to ask the bookies for a quote.

Of great interest tomorrow will be whether co-trainer Bob Vance accepts for the Guineas on Sunday with Castlzeberg or believes he can get him to the Derby fit enough without another run.