Star apprentices Tegan Harrison and Anthony Allen make their metropolitan racing debuts as senior riders at Eagle Farm on Saturday.

It signals a changing of the guard in the Brisbane apprentice ranks as Harrison and Allen have dominated the junior premierships for the past three seasons.

They two were given extensions on their apprenticeships to the end of the 2013/14 season as they battled out the title.

In the end Harrison won her second championship comfortably with 43 winners to Allen's 34.

Both outrode their allowances with Harrison achieving the milestone in March and Allen last week.

Harrison, who originally trained as a nurse, was the first female apprentice to win Brisbane's junior title and the first to outride her allowance.

Her biggest wins have come this season aboard Temple Of Boom in the Group Two Victory Stakes and Brave Ali in the Listed Ipswich Cup.

"I have been riding without an allowance for four months and trainers such as Tony Gollan have stuck with me," Harrison said.

"I realise there are challenges ahead but I am looking forward to it."

Allen, who is partially deaf and wears hearing aids, is also determined to make a go of racing in his senior years.

"I have ridden all over the state and it is a matter of cementing relationships with trainers. I would love to challenge for the senior jockeys title," Allen said.

Allen set his own records as a junior rider and in 2012 became only the second apprentice in Brisbane to ride five metropolitan winners in a day.

Harrison has six scheduled rides on Saturday's program while Allen has two.