Under the watchful eye of Bart Cummings, So You Think's former trainer, Leung fought off some spirited bidding before the hammer fell at $800,000.
Offered by Windsor Park Stud, the colt by High Chaparral from La Souvenir (a daughter of So You Think's dam Triassic) was bred by the stud's marketing manager Mike Moran, in partnership with his wife Helen and Chris and Carol Chamberlain.
They bought Triassic for a modest $16,000 and the rest, as they say, is history.
Triassic produced So You Think which sold for $110,000 at Karaka in 2008 and now - under the care of Ireland's Coolmore Stud - has a reputed value of some $60 million.
Leung described the La Souvenir colt as a "lovely horse, big, strong, athletic" and said he would remain in New Zealand for the next 12 to 18 months to be given time to develop.
"Hopefully, we can run him as a 3-year-old here or in Australia to prove how good he is."
Unlike many horses bought by Hong Kong buyers, the colt will remain an entire to preserve his stallion potential.
"His temperament looks OK so we'll try to keep him as a colt as long as possible," Leung said.
On Monday, the same Hong Kong buyers outlaid $650,000 for a High Chaparral-Creil colt offered by Lyndhurst Farm.
With the High Chaparrals doing well in New Zealand, Australia and Europe, Leung said: "We're very happy to get both top colts that we believe are the best in the sale".
The ultimate goal, he said, was to develop top stayers with Melbourne Cup potential.
"That would be the dream, and we'll try to make the dream come true."
