Aidan O’Brien will unleash one of his big guns in a bid to take down reigning champion Romantic Warrior and win his first Group One Longines Hong Kong Cup (2,000m) at Sha Tin next month.

On an international rating of 123, Luxembourg is set to be the highest-rated galloper the Irish master has sent to the city since globetrotting superstar Highland Reel.

Highland Reel snared his second Group One Hong Kong Vase (2,400m) victory off a mark of 123 in 2017 – the same international rating Luxembourg and local hero Romantic Warrior share ahead of their mouthwatering clash in the city’s richest race on December 10.

Japan will again launch a strong assault on the HK$36 million Cup, with Prognosis, Rousham Park and Hishi Iguazu set to make the journey from the Land of the Rising Sun, while Patrice Cottier’s exciting three-year-old Horizon Dore will fly the French flag.

Luxembourg is one of 16 international Group One winners among the fields for the HK$118 million Longines Hong Kong International Races (HKIR), with 25 overseas raiders setting their sights on the day’s four features – four more than lined up at the marquee meeting 12 months ago.

A half-length second behind brilliant stablemate Auguste Rodin when last seen in the Group One Irish Champion Stakes (2,000m), four-year-old Luxembourg boasts top-level successes in May’s Tattersalls Gold Cup (2,100m), last year’s Irish Champion Stakes and the 2021 Vertem Futurity Trophy Stakes (1,600m) as a two-year-old.

Horizon Dore is the next highest-rated galloper in the field, but the gelding is still chasing his breakthrough Group One success after finishing third behind King Of Steel and Via Sistina in the Champion Stakes (2,000m) at Ascot last month in his first top-level assignment.

Prognosis looks the best of the Japanese trio and brings Equinox form to HKIR after finishing three and three-quarter lengths behind the world’s best horse when third in the Group One Tenno Sho Autumn (2,000m) at Tokyo on October 29.

Prognosis takes aim at Romantic Warrior for a second time after closing late for second behind Danny Shum Chap-shing’s superstar in April’s Group One QE II Cup (2,000m), while Hishi Iguazu is also known to Hong Kong fans.

Ninth in that Equinox race last start, Hishi Iguazu finished a narrow runner-up behind Loves Only You under Joao Moreira in the 2021 Hong Kong Cup and will tackle the race again as a seven-year-old.

Rousham Park will come to Hong Kong on the back of three straight wins but will make his Group One debut after taking out the Group Two Sankei Sho All Comers (2,200m) in September.

After creating history with victory in the Group One Cox Plate (2,040m) at Moonee Valley last month, Romantic Warrior will bid to become the first galloper since California Memory in 2011 and 2012 to snare consecutive Hong Kong Cup victories.

Also among the seven-strong local contingent are last year’s third placegetter Money Catcher and last weekend’s Group Two Jockey Club Cup (2,000m) victor Straight Arron, while Sword Point, Nimble Nimbus, Running Glory and Champion Dragon round out the home team.