Melbourne trainer Pat Hyland believes Theseo is the weight-for-age benchmark in Australia and rates him the biggest threat to Zarita in the Group One $2.25 million BMW.Punters are clamouring to back Melbourne Cup winner and heavy track performer Viewed who is the TAB Sportsbet favourite at $2.20 ahead of Theseo at $4 while Zarita is rated a $15 chance in the 2400-metre feature at Rosehill on Saturday.But rather than Viewed it is the last-start Ranvet Stakes (2000m) winner Theseo from the Gai Wat

Melbourne trainer Pat Hyland believes Theseo is the weight-for-age benchmark in Australia and rates him the biggest threat to Zarita in the Group One $2.25 million BMW.

Punters are clamouring to back Melbourne Cup winner and heavy track performer Viewed who is the TAB Sportsbet favourite at $2.20 ahead of Theseo at $4 while Zarita is rated a $15 chance in the 2400-metre feature at Rosehill on Saturday.

But rather than Viewed it is the last-start Ranvet Stakes (2000m) winner Theseo from the Gai Waterhouse stable who Hyland is convinced will be the horse to beat.

"There's no doubt that he is the benchmark at weight-for-age in this country and if we can get on top of him we can win the race," Hyland said.

"And if you look at the way she's performed against Theseo, she hasn't been far away from him recently and we beat him home in the Cox Plate."

Zarita ran fourth in last year's Cox Plate (2040m) with Theseo fifth.

The Rosehill surface was rated a heavy nine on Friday after more than 60 millimetres of rain since Monday and track manager Lindsay Murphy expects the track to stay in the heavy range.

Four-year-old Zarita has never raced on a heavy surface but the bulk of her wins have been on dead tracks.

"Most of those tracks were more like slow tracks, having walked them before the race, and I think she'll handle the going on Saturday," former champion jockey Hyland said.

Hyland believes winning over 2500 metres in the Group One South Australian Derby would also hold Zarita in good stead.

"That's got to give us some sort of edge," Hyland said.

"Viewed will obviously handle the trip and the heavy going has put him in the picture.

"But in the Ranvet Stakes I thought Theseo won well while the others were in a bunch behind him including Viewed and you just wonder about the weight-for-age class of that race aside from the winner."

Although he doesn't have a runner in Saturday's $3.5 million Golden Slipper, Hyland will be keeping a close eye on the race he won aboard Vain in 1969.

If Rostova wins the Slipper jockey Steven King will join an elite group, which includes Hyland, to have won racing's grand slam.

Hyland, along with Neville Sellwood, Roy Higgins, Mick Dittman, Jim Cassidy and Damien Oliver, won the Melbourne Cup, Caulfield Cup, Cox Plate and Golden Slipper.

"I hope Steven can do it," Hyland said.

"It's no fluke for a jockey to win all of those great races, it's a huge achievement and something I am very proud to have done.

"These races create history and when you win them you are part of that history, it's a great feeling knowing you've won all of the big ones and it's something you really appreciate in retirement."