World's top-rated horse Equinox faces toughest test to date in Sunday's star-studded Japan Cup

Equinox will face the strongest challenge yet to his position as the world’s highest-rated horse, gained in the Dubai Sheema Classic in March, when he starts a hot favourite for the Japan Cup in Tokyo on Sunday.

Seven other Group 1 winners are in a full field of 18, including the sole overseas contender, French-trained Iresine, who attempts to end a run of 17 consecutive victories for local horses in a race that will be televised live by Racing TV for the first time.

As a further indication of the quality of those taking on Equinox, he and Iresine are among five runners who feature in the latest list of the top 50 Longines World’s Best Racehorse Rankings, in first place with a rating of 129 and joint 34th on 120.

Iresine, trained in Lyon by first-time visitor Jean-Pierre Gauvin, has been a revelation under regular partner, France’s leading female rider Marie Velon, and arrives after wins in the Prix Ganay and Prix du Conseil du Paris and two honourable seconds this year.

Immediately behind Equinox in the ratings is Titleholder (124), whose mark was logged in March, followed by Do Deuce (120), the last horse to beat the local champion in the Japanese Derby in May 2022, and the enigmatic Panthalassa (120), this year’s Saudi Cup winner who has not raced since finishing down the field in the Dubai World Cup on dirt.

All four have been beaten by Equinox at one time or another, since he started a five-race unbeaten sequence in Group 1 races, as has last year’s winner Vela Azul, on whom Hollie Doyle is a late replacement for injured Ryan Moore.

Vela Azul: last year's Japan Cup winner will be ridden by Hollie DoyleCredit: Masakazu Takahashi

And that appears to leave Liberty Island as the biggest unknown quantity. As a three-year-old filly, she receives weight all round, and the equivalent of almost 9lb from all but three of her rivals, including Equinox.

Always ridden with patience, she has unleashed a devastating late turn of foot to win all three outings this year in a sequence comprising the fillies’ Triple Crown. Dual Japan Cup winners Gentildonna and Almond Eye won the same trio of fillies’ Classics.

Liberty Island’s clash with Equinox has captured the imagination of Japanese racing fans, who are always quick to latch on to a favourite horse. However, Tetsuya Kimura, the 51-year-old trainer of Equinox, deflected attempts to make comparisons when questioned by the international media at the Miho training track on Friday.

Choosing his words carefully, even in his own language, he said he preferred to concentrate on his own horse, whose sire Kitasan Black won the Cup in 2016. Nor did he fall for attempts to get him to reveal tactics, to which he responded: “I don’t give too precise instructions to my jockeys, and we have a very good combination with Christophe Lemaire, who has ridden Equinox in all his races.”

Kimura did betray a slight sense of concern about the relatively short time since Equinox’s last race, a month ago, when he won the Tenno Sho (Autumn) for the second time. “It’s a challenge,” he said, “because the level of Group 1 races in Japan has improved, so horses use all the energy they have in these races. How he will cope on Sunday is one of the challenges.”

Otherwise, he said, the preparation had been smooth, adding: “He worked well on the training track this morning and I am relieved he has done all his work as expected.”

As to the future for the four-year-old, Kimura was adamant. “There are no concrete plans for after the Japan Cup,” he said. “My 100 per cent concentration is on Sunday.”

There was a late scare for connections of Iresine, the sole overseas challenger for Sunday’s Japan Cup, when he was found to be slightly lame at evening stables on Friday. He had a bruised foot, which was believed to have been caused by an ill-fitting leather pad on one hoof.

However, French trainer Jean-Pierre Gauvin reported on Saturday morning that all was well with the six-year-old. “We took measures on Friday,” he said, “and this morning, after working him with and without shoes, he was sound.”

Japan Cup (Sunday, 6.40am)

Bet365: 2-5 Equinox, 9-4 Liberty Island, 16-1 Do Deuce, 18-1 Titleholder, 20-1 Stars On Earth, 33-1 bar

Read these next:

The age of Equinox: could the Cox Plate and Tenno Sho be just the start of a huge week for the eastern powers? 

Hollie Doyle to ride in Japan Cup for first time on last year's winner with Ryan Moore injured 

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