In the end it wasn't quite a fairytale start or ending for Sydney's new racing festival, but it came close.

The Championships at Royal Randwick kicked off under leaden skies and received regular soakings but 25,000 people still turned out, determined to make it a party.

Sydney's answer to the Melbourne Cup carnival, The Championships are an international-standard racing carnival with $18 million in prizemoney offered over two consecutive Saturdays.

As far as international race meetings go, The Championships have it all: big prizemoney, international horses and superstar jockeys and a touch of trackside glamour.

Add to that not one but two touches of royalty.

A visit from new Governor-General Sir Peter Cosgrove to officially name the new Queen Elizabeth II grandstand was complemented by a special video appearance by Prince William, ahead of his arrival in Sydney on Wednesday.

The Australian Turf Club has promoted The Championships heavily.

As the opening day for a new era of Sydney racing, The Championships were hurt by the weather: 25,000 turned out instead of a hoped-for 30,000.

On the track, which was rated heavy because of the rain, sentimental crowd favourite jockey Tommy Berry didn't win the headline race, the $3 million Doncaster Mile, but had thousands shouting themselves hoarse on his way to a minor placing.

Berry, who tragically lost his twin brother and fellow jockey Nathan to illness 10 days ago, still rode a winner, dedicating the victory to his sibling.

Off the track, supermodel Jennifer Hawkins oversaw judging of the finest fashions in keeping with the traditional black and white theme of Derby Day.

Ahead of race day, fashionistas had expressed a hope that Sydney racegoers might bring a touch of more sedate Melbourne style to their raceday attire.

Some took the message on board but away from the marquee areas and the member's stand, the more traditional Sydney race uniform of colourful, short skirts and towering, tottering heels was still proudly on display.

In another innovation, 700 of Sydney's most beautiful people crowded into the $695-a-head Little Sydney entertainment precinct to enjoy fare from some of the city's best restaurants.

The verdict of the punters elsewhere was positive, even in the rain.

Saturday's event was the biggest since the recently refurbished Randwick complex reopened, and its "Theatre of the Horse" parade enclosure found particular favour with one of the youngest racegoers.

Shane Murray, a 22 year-old Irishman resident in Maroubra, had his 16-month-old son Jake along and the toddler, on his first-ever race day, was happy to get up close with the thoroughbreds at the parade ring.

Mr Murray was happy too.

"I've won $50 on the first race and $20 on the second," he said.

In the members' stand, Ben Maher and his father Reg were impressed by the standard of racing.

The Mahers are relatives of Danny Maher, an owner of the Gai Waterhouse-trained horse Sweet Idea who was racing in one of the feature events.

Mr Maher jnr said the prizemoney on offer had meant quality horses and attractive racing that had kept people watching even in the rain.

"Because of the prize money we have the best horses and the cream has risen to the top," he said.

He said The Championships wasn't the Melbourne Cup.

"It never will be and they shouldn't try to be."

But the carnival had put racing in front of a much broader audience.

"Everyone in Sydney knows the Championships are on - it's an event whereas before it was just a race day," he said.

"All in all, definitely a success."