Gai Waterhouse says the return of Nash Rawiller can be the spark to propel Rock Kingdom into an illustrious group of gallopers from the famous Tulloch Lodge.Victory in Sunday's Group Three Summer Cup (2400m) on his home track at Randwick would make Rock Kingdom racing's latest million-dollar earner.A study of the trainer's own Hall Of Fame on her website reveals Rock Kingdom would become the 33rd Waterhouse-trained Group One galloper to have earned more than $1 million in prizemoney.Waterhouse's

Gai Waterhouse says the return of Nash Rawiller can be the spark to propel Rock Kingdom into an illustrious group of gallopers from the famous Tulloch Lodge.

Victory in Sunday's Group Three Summer Cup (2400m) on his home track at Randwick would make Rock Kingdom racing's latest million-dollar earner.

A study of the trainer's own Hall Of Fame on her website reveals Rock Kingdom would become the 33rd Waterhouse-trained Group One galloper to have earned more than $1 million in prizemoney.

Waterhouse's stable rider Rawiller missed Rock Kingdom's last-start second in the Listed Christmas Cup (2400m) as he was in Hong Kong on a short break after competing in a jockeys' challenge.

"Nash is there to ride him and the other jockeys, as good as they are, don't know my horses as well," Waterhouse said.

"The lovely thing about a horse like that is that Nash knows him so well. It's half the battle because he's there every day."

Since his week away in Hong Kong, Rawiller has been in outstanding form riding eight winners at just four city meetings since his return.

Rock Kingdom has earned $968,750 with another $75,000 on offer to the winner of the summer staying feature.

The gelding hasn't found the winner's circle since his Group One Epsom Handicap triumph in October last year, but recent performances have been encouraging enough to suggest he is knocking on the door of another feature win.

"It's the most winnable race for him and I can't see him doing anything wrong," Waterhouse said.

"I couldn't be happier with him, he's thriving in training and he's well placed in Sunday's race."

Waterhouse said Rock Kingdom had many things in his favour in the Summer Cup as he looks to go one better than runner-up performances in the Listed Canberra Cup (2000m) and Christmas Cup (2400m) at his past two starts.

The son of Rock Of Gibraltar drops to 58.5kg after his second to Bellagio Wynn with 59.5kg on December 11.

"I think (the weight relief) is definitely a help and he's just a happy chappy," Waterhouse said.

"He's working so well and has raced well through the Melbourne carnival and is still doing it."

Aqua D'Amore, winner of the 2007 Group One Futurity Stakes and $1.9 million in prizemoney, was Waterhouse's most recent of five Summer Cup winners in 2005.