The Toorak Handicap is the lowest-profile of Saturday's three Group One races at Caulfield, but it has the potential to be the race that everyone leaving the course is talking about.

More Joyous will make her Victorian debut in the $350,000 feature - that complements the Caulfield Guineas and the Yalumba Stakes - and the Gai Waterhouse-trained four-year-old will have to be every bit as good as Sydneysiders are proclaiming if she is to take out one of Victoria's premier 1600m events.

The daughter of More Than Ready has earned comparisons with the Sunline thanks to her deeds so far this spring and she will need to produce a performance of which the former champion Kiwi would be proud to win the Toorak.

Allotted 58kg for the race that has been won by Tobin Bronze, Galilee and Gunsynd, More Joyous will set a modern-day mares' weight carrying record if successful.

In the last 50 years, the heaviest impost carried to victory by a mare was 57.5kg by Ripa in 1965. Canny Lass and Divine Madonna, who carried 55kg in 1986 and 2007 respectively, are the only other mares to cart more than 52.5kg to victory since 1960.

But if any mare can do it, it's More Joyous. A winner of nine of her 12 races all up, she has been breathtaking in winning her past seven starts including three this campaign.

After shouldering 59kg to beat the girls over 1100m first up, she triumphed in the Group 2 Theo Marks Quality (1300m) before securing Group 1 glory in the George Main Stakes (1600m) at her most recent outing.

While the weight is against her, in her favour is the fine recent record of mares in the Toorak. The fairer sex went 16 years without winning the Toorak after Ricochet Rosie's win in 1990, but they have won two of the past three thanks to Divine Madonna and last year's winner Allez Wonder.

The Bart Cummings-trained Allez Wonder has the task of joining Umrum, Nicopolis, Desert Breeze and Saxony as the only multiple winners of the race first run in 1881 and she will have to do it with 53.5kg - 1.5kg more than she carried to victory last year.

Response, Avienus and Ghostmilk are the other mares in Saturday's race, with Response striving to become the ninth winner of the Sir Rupert Clarke Stakes-Toorak double.

More Joyous's appearance gives racegoers a look at the three favourites for the Cox Plate on Saturday with So You Think and Whobegotyou to round out their preparations for Australia's weight-for-age championship in the $400,000 Group 1 Yalumba Stakes.

The high-profile duo have scared off most of the opposition with only four other rivals to contest the 2000m, but that won't detract from the race's importance as a key Cox Plate lead-up.

The Yalumba had been a nightmare race for punters until Whobegotyou won at $2.15 last year with El Segundo (2006) and Miss Finland (2007) two who went down as odds-on favourites in recent years.

Ironically, Whobegotyou will be out to deny favourite backers this year. So You Think will be the punters' pick as the son of High Chaparral, also trained by Cummings, looks to maintain an unbeaten spring that has so far produced wins in the Group 2 Memsie Stakes and Group 1 Underwood Stakes.

The defending Cox Plate champion will become the first horse to pull off the Memsie-Underwood-Yalumba treble in the past 20 years if he makes it six wins from just nine career starts this weekend.

Despite the interest in the Toorak and the Yalumba, Saturday's main event is the $1 million Caulfield Guineas (1600m).

This year's edition shapes as a good old fashioned Melbourne versus Sydney stoush with the host city represented by Toorak Toff and Sydney's hopes riding with Ilovethiscity.

The star pair have only met once, in the $1 million Golden Rose, when Toorak Toff got the prize and Ilovethiscity was a desperately unlucky third.

The Grahame Begg-trained gun bounced back to score a deserved win in the Spring Stakes at Newcastle at his next start and is in the running to become the first horse since Encounter in 1997 to complete the Spring Stakes-Guineas.

Toorak Toff, who is trained by Rick Hore-Lacy, the man who prepared Redoute's Choice to win the most memorable Guineas of all in 1999, will join In Top Swing as the only Golden Rose winner to go on and claim the Guineas if successful.

But Saturday's highlight's don't stop with the Group 1s with unbeaten mare Black Caviar to make her long-awaited return in the $200,000 Group 2 Schillaci Stakes, while Caulfield Cup fancies Precedence and Moudre need to win the Group 2 Herbert Power Handicap to earn a spot in the first leg of Australian racing's most prized double the following week.