Apprentice Ethan Brown has notched a career milestone, outriding his metropolitan claim after guiding Fidelia to victory at Flemington.

Saturday's win in the So You Think Hall Of Fame Trophy was Brown's 24th metropolitan success for the season and he leads the Melbourne apprentices' title by four from Michael Poy.

A sought after apprentice, especially for Darren Weir, Brown found his opportunities dry up when that trainer was disqualified in February for four years.

Brown sought an extension to his apprenticeship in a bid to outride his claim before joining senior ranks.

"I've been waiting for this day for a very long time," Brown said.

"I can't explain the feeling really but it's something I've been working towards for a very long time.

"I've got a lot of people to thank. Weiry's one of them and my boss Mick Kent but there's a lot out there and they know who they are."

Sitting back in the field at her first try at 1600m, Fidelia, the $2.30 favourite, hit the lead before the 200m mark before holding off a late bid from Sure Knee, backed from $4.60 to $3.40, to win by a head.

"I was very casual on her," Brown said.

"Her turn of foot catches me off-guard all the time. Usually you press the button and they build into it, but she has instant speed.

"She's a very nice horse going forward and she definitely got the mile fine."

Brown's day was soured with an eight-meeting careless riding suspension on Arancini in the National Hall Of Fame Handicap.