Japan-stabled Rulership sprinted to victory Sunday in Hong Kong's HK$14-million ($1.8 million) Audemars Piguet QE II Cup, producing a career-best run under Italian jockey Umberto Rispoli.

The five-year-old finished three lengths in front of local runners Thumbs Up in second and the bookies' favourite Sweet Orange in third spot on the 2,000-metre turf track, which was sodden after heavy overnight rain.

"It's a dream for me," 23-year-old Rispoli said after the perfect end to his Hong Kong season before he moves to France to try his luck in Europe.

"The horse responded very well in the last 300 metres. He ran very well and I'm very happy."

The jockey stood and gestured to the crowd as he passed the post at Hong Kong's Sha Tin racetrack in the World Racing Championship event.

From the stable of Japanese trainer Katsuhiko Sumii, Rulership was one of four foreign horses to make the trip to Hong Kong for the race.

The son of Air Groove, he is a three-time Group Two winner but had yet to win at this level, and had only raced overseas once before.

Sumii said he was not confident going into the race.

"I was worried about the competition and he hasn't won a Group One before, so I was a little worried," he said.

"Hong Kong is a favourite place for me."

Rulership was the only foreign entry to finish in the top seven. Top local trainer John Moore's two runners, Zaidan and Irian, finished fourth and seventh respectively.

California Memory, last year's QEII runner-up to Ambitious Dragon and winner of the Hong Kong Cup in December, placed fifth from an outside draw.

Sweet Orange was the strong favourite from the second gate on the wet track, but was edged into third by a nose from outside-starter Thumbs Up ridden by Australian jockey Brett Prebble.

Rulership drew eight of 13 runners but was among the leaders early and found himself on the inside track by the time they rounded the last bend, then broke free to a comfortable win.