An emotional Roger James has declared Prowess the best horse he has trained after the star New Zealand filly's explosive win in the Group 1 Vinery Stud Stakes at Rosehill. 

But he won't be tempted into keeping her in Sydney for the ATC Australian Oaks (2400m), believing she is not a genuine stayer and has bigger fish to fry as an older mare. 

Fighting back tears, James, who has put the polish on top-class gallopers the ilk of Zonda and Silent Achiever, said Prowess surpassed them in ability and race smarts and was still untapped. 

"I could have waited forty years for this one. She's special," James said. 

"She does things that I haven't had another horse be able to do and I've been very blessed. I've had Zonda, who was always the benchmark, Silent Achiever. I've had some lovely horses over the years. 

"I've won this race with Sixty Seconds, but this filly does special things. 

"I've thought it for a long time, that she could be the best I've trained. She is a superstar this filly." 

Prowess had won six of her eight appearances in New Zealand but it was her last-start Group 1 win against the older horses that marked her as a special talent. 

She was sent out a $2.15 favourite on Saturday with VRC Oaks runner-up Pavitra ($3.40) considered her only genuine rival. 

However, Prowess made the Vinery Stud Stakes (2000m) a one-act affair, unleashing a powerful turn of foot to race clear and beat Pavitra by 3-1/4 lengths with Fireburn ($11) another three-quarters of a length back third. 

Prowess is entered for the Oaks (2400m) at Randwick during The Championships but James says she will be heading back to New Zealand on Sunday. 

"The world is her oyster. Without being silly, there is a lot of money to be had as an older horse in Australia and she's had quite a big season," he said. 

"She's been to the South Island and back, she is still learning her game too. We'll get home and enjoy what we've just seen now and we can make plans from there." 

Mark Zahra picked up the winning ride on Prowess from a suspended James Mcdonald and in the process collected his 25th Group 1 win. 

He was in awe of the filly's performance, saying "I was able to sit up and enjoy the Group One". 

"Sorry to 'J Mac', but he's got near 100 (Group 1 wins) and another 100 coming in the next year so I'll take one," Zahra said. 

"It was nice to get a pick-up ride like that and she was a level above." 

Chad Schofield on Pavitra said the race went to plan and she ran well but the winner was far superior. 

"We got beaten by an absolute weapon," Schofield said.