Trainer Cindy Alderson admits Tycoon Bella has been a surprise packet and she hopes the filly can continue her winning ways when she makes her metropolitan debut at Flemington.

After victories at Mornington and Ballarat at her first two starts, Tycoon Bella faces a stiffer test in Saturday's December Twilight Handicap (1400m).

The three-year-old is the highest-rated runner in Saturday's race following her win in the VOBIS Gold Stockade (1400m) under Luke Currie on November 23, but Alderson concedes there are some in-form rivals to overcome.

Alderson also said it was hard to gauge Tycoon Bella's ability as the filly did not extend herself at home.

“She's very laid-back,” Alderson said.

“Even before she won her first race she didn't show us much. She kept winning (her trials) but she wasn't flashy or anything like that.

“But sometimes those are the best horses because they're keeping a little bit back in reserve.”

While surprised by the strength of Tycoon Bella's Ballarat success, Alderson said she took encouragement from Currie's post-race assessment that he felt the filly had more to give.

But the trainer also cautioned that a number of the filly's opponents that day had been through tough spring campaigns and the race may have been an afterthought for some.

“She definitely landed in the right spot and had the right run in the race, but she still ran good sectionals and she powered to the line, so we'll see what she does,” Alderson said.

“Three straight, it's hard to do.

“And Saturday, it's a hard race as there's a few in there that have got good form lines, but she's drawn a good barrier again and it will be interesting to see how she fits.”

Mindful Tycoon Bella is in her first racing preparation, Alderson says she is likely to be spelled after her Flemington assignment.