Neorealism (Image: Hong Kong Jockey Club)
Winx could be thoroughly tested in her attempt on a third Cox Plate if the Japanese galloper Neorealism contests October's $3 million race according to Racing Victoria's executive general manager of racing Greg Carpenter.
Neorealism - the QEII Cup winner in Hong Kong in May over local heroes Pakistan Star and Werther - is one of 15 international entries for the October 28 Cox Plate and one of 141 horses to nominate for Australia's weight-for-age championship at Tuesday's noon closing time.
Carpenter said the entry from UK star Lightning Spear was noteworthy as were the six entries from Aidan O'Brien, headed by his English Derby runner-up Cliffs Of Moher as well as Highland Reel, who has won six Group 1 races across three countries since he was beaten into third place by Winx in the 2015 Cox Plate.
But he said Neorealism posed the biggest threat to Winx's attempt to equal Kingston Town's triple Cox Plate feat (1980-82).
"He is one of the outstanding 2000-metre horses on the world stage," Carpenter said.
"When he beat Maurice last year he led all the way and then in Hong Kong, off a slow pace in the QEII Cup, Joao Moreira took off at the halfway mark, circled the field and took the lead and was able to hold off Pakistan Star and Werther.
"He has all the attributes."
The total international contingent includes seven horses from Ireland, seven from the United Kingdom and one from Japan.
Nominations also closed on Tuesday for the $500,000 Schweppes Thousand Guineas for three-year-old fillies, and the stallion-making Ladbrokes Caulfield Guineas, the latter of which received 327 nominations off the back of the doubling of prizemoney by RV to $2m.
Victoria's richest three-year-old race and the Thousand Guineas, which received 237 nominations, will both be run on Caulfield Guineas Day at Caulfield on October 14 - two weeks prior to the running of the Cox Plate.
Carpenter said the enormous interest in the Caulfield Guineas, coupled with the wonder of Winx and the depth of her international competition, has set the scene for a sensational month of spring racing in October.
Carpenter said it may be that we see the winner of this year's Cox Plate come from a race two weeks earlier in either the Caulfield Guineas or Thousand Guineas, with 44 three-year-olds entered for the Cox Plate.
"There is no doubt that the huge number of Caulfield Guineas entries (327) received today is in direct relation to the rise in race prizemoney, which has doubled to $2 million as part of major prizemoney increases announced in May," Carpenter said.
"It is one of the strongest Caulfield Guineas we've ever seen with the leading stars of the autumn such as Catchy, The Mission, Invader, Summer Passage and the story of the winter, Royal Symphony, among the leading contenders to take home the $2 million purse and then pursue the Cox Plate two weeks later."
Moonee Valley Racing Club chief executive, Michael Browell, said the countdown to the 97th running of the Cox Plate has begun.
"It is pleasing to see a number of internationals come through and the best of local talent nominated to take on the challenge that is Winx," he said.
"Last year's race was rated 124.75, the equal-second-highest race in the world and best race on turf at the 2016 Longines World's Best Horse Race Awards and we're aiming to reach that number one spot in 2017," Browell said.
View the full list of Cox Plate nominations.
View the full list of Caulfield Guineas nominations.
View the full list of Thousand Guineas nominations.