Last Saturday star Sydney trainer Gai Waterhouse unveiled another possible Group One cups winner with her emerging four-year-old Reuben Percival scoring an extraordinary five length win in the Stayer’s Cup in Sydney.

Al Akbar gelding Reuben Pericval went out as a $5 chance in the $100,000 Stayer’s Cup (3200m) at Rosehill following a number of promising runs this season.

Ridden to perfection by Tommy Berry, Reuben Percival emerged as an authentic two-mile runner easily accounting for their five rivals in the feature.

On the line Reuben Percival had five lengths to spare over Splendid Honours ($13) with Chris Waller’s $2.40 favourite and defending winner Strike One could only managing to finish third ahead of their also highly-fancied stablemate Patrician’s Glory ($3).

The lightly-raced champ has now started 11 times for two wins and four minor placings earning over $83,000 in prize money to date.

Reuben Percival joined Waterhouse in her Sydney stables during the summer, before which the promising galloper was raced in New Zealand.

The Stayer’s Cup was not only their break-through win in Australia, but was also their first test over the gruelling 3200m distance.

Handling the step up in distance with surprising ease, Reuben Percival has emerged as a genuine Group 1 chance in features including the iconic Sydney Cup (3200m) in the autumn next year.

“He has always showed staying prowess and looked like he would just stay all day so it was great to see him deliver,” Waterhouse’s stable representative Bruce Slade said.

“There’s a question mark on what Gai will do with him now.

“Physically he’s still a preparation away and Gai will probably look to turn him out now.

“He could have a light let-up and come back for the spring, but most likely he’ll have a good two months out and come back for a late summer and autumn campaign.

“The Sydney Cup is the sort of race Gai has in the back of her mind.”

Jockey Berry was also impressed with Ruben Percival’s performance over the 3200m and tipped him as a stayer to watch in the future.

“This horse pulled up and didn’t even have a blow,” Berry said after the Stayer’s Cup win.

“He really sprinted and I took it easy on him the last 200 metres so there’s plenty of upside.”

Waterhouse’s veteran stable foreman David Meijer revealed that Ruben Percival had been purchased in New Zealand by Gai on recommendation from her husband Rob.

Rob Waterhouse was also the mastermind behind Gai’s maiden Caulfield Cup winner Descarado, another Kiwi galloper.

“Descarado is back in work and did his first bit of pacework yesterday,” Meijer said on Saturday.

“We are happy how he has come back and Tullamore is having two weeks in the paddock and we’ll look at some of the cups in Melbourne come spring time.”

Savabeel gelding Tullamore was the upset winner of the Group 2 Brisbane Cup (2400m) at Eagle Farm on June 11, the emerging stayer able to beat home raging favourite Glass Harmonium in the feature.