It is the smallest Group One field assembled at Randwick on Saturday but the Flight Stakes has punters divided.

The two horses who have claimed the middle legs of the four-race Princess series, Winx and First Seal, are vying for top billing in the final and most important three-year-old fillies race of the Sydney spring.

In a field reduced to seven by the scratchings of Twirl and Muscovado, Winx eased slightly on Friday to join First Seal as the $2.50 equal favourite.

Winx suffered her first defeat at her fourth start when First Seal beat her in the Tea Rose Stakes.

First Seal's jockey Blake Shinn respects Winx but is adamant his mount will relish the 1600 metres on Saturday.

"It's going to be a great race," Shinn said.

"But my girl has made natural improvement and I think the mile is going to suit her."

Chris Waller, trainer of Winx, is equally upbeat and thinks the distance rise from the 1400m of the Tea Rose favours his filly.

"The step up to a mile will really suit our filly," Waller said.

"The other horse beat us fair and square last start, I don't deny that, but Winx wasn't disappointing. That's just racing."

First Seal is an important horse for trainer John Thompson as he begins the post Patinack Farm era after a dispersal sale of his former boss Nathan Tinkler's horses this week.

The filly is owned by a group which includes the China Horse Club which is instrumental in the fledgling racing and breeding industry in China.

As late-season two-year-old winners, Winx and First Seal have similar profiles and both fillies are nominated for the VRC Oaks.

The only rival rated a serious threat to them on Saturday is unbeaten Victorian Thinking Of You.

Trainer Peter Moody has scratched her from the Edward Manifold Stakes at Flemington to contest the Group One in Sydney where she will be aiming to go one better than stablemate Sensibility who was runner-up to Guelph in the race last year.