The five-year-old took the spoils by three quarters of a length and, in doing so, dented a reputation or two, though not that of runner-up Columbus County (119lb) who enhanced his Four-Year-Old Classic Series prospects with an unlucky run to second.
"No doubt about it, he's very unlucky not to win – if he hadn't had horses snaking around in front of him, he would have won," jockey Joao Moreira said of the Caspar Fownes-trained runner-up.
"It's a promising run for the future," he added.
The New Zealand import was beginning to hit his stride on a closing run at the 300m mark when fellow four-year-old Private Secretary rolled out and stalled his charge. The Redwood gelding recovered to rattle home at only his second Hong Kong start.
But the spoils belonged to Preciousship, a revelation this season with three wins from five starts, having failed to trouble the judge through eight races last term.
"It's another impressive win, he's a gutsy little horse. I said to the owner before I bought him, he could be one of the best milers – he tries very hard and loves his races," Yiu said.
"Today's the second time the jockey came in and said that when he hit the front he slowed down, he's looking for something to come to him."
The bay raced as Riyazan in Ireland where he won a 1400m Dundalk Listed race and was almost five lengths fifth of five to Saxon Warrior in the G2 Beresford Stakes.
"I kept telling the owner to give him some time to acclimatise, he's a European import, they need time – you have to wait for the penny to drop and once he's there, he'll hold his form for a long time."
Yiu's win took him to 33 for the season, six clear of Francis Lui in the trainers' title race.
"I'll keep my position the best I can," Yiu smiled.
As for the dented Classic Series reputations, Brazilian G1 winner Butterfield boxed on for sixth, but the well-regarded Private Secretary was unable to reproduce his stylish debut win and crossed the line a tame 10th.
Whyte's young prospects shine
Douglas Whyte's success with his young stock continued with wins this afternoon for his smart prospects Farhh Above and Inner Flame.
Farhh Above returned from a lay-off for his belated seasonal debut and charged emphatically from the tail to snare the Class 3 Nga Tsin Wai Handicap (1200m) under Vincent Ho, clocking a swift 21.62s for the final 400m.
"He's a lovely horse; he's got a very good turn-of-foot. To let down the way he did, that was a very good effort," Whyte said.
The four-year-old – trained by Francis Lui previously – was a decent second to the G1-placed sprint star Aethero on debut last term and followed that with a win, suggesting he could turn out to be a viable Four-Year-Old Classic Series prospect. With the first leg of that series, the Hong Kong Classic Mile, set for 27 January, Whyte was reluctant to commit to such a route but did not dismiss altogether the colt's participation at some stage of the three-race test.
"It's always at the back of your mind on what he did," Whyte admitted, "but then everything slows down and goes out the window when he's had that much time off and you've got to nurse him back and put him in cotton wool. He's been out of cotton wool for a while now and he's answered everything I've asked of him in order to be competitive first-up.
"He had to be competitive first-up if he's to compete in any of the Series," he continued. "The problem is he's just run out of time; time is against him. He's probably a month behind and I refuse to look at a race and say we're going for that – it's all about him. It's taken that long to get him to the races I'm certainly not going to ruin him by finding a race and putting him in because it's part of a series, or a big race. I've got too much respect for the horse and I think he's too good a horse to be doing that with."
Farhh Above was diagnosed with bone stress in his limbs at the end of September and Whyte took a patient approach before placing him in a couple of barrier trials during December, the latest at Happy Valley.
"Fingers crossed he can improve on that run," the first-season handler said. "Any horse that can come from last to first the way that he did it, on a track like today, it's got to be a nice horse in the making.
"It's all about the horse first and he'll indicate to me when we're next going to turn up at the races. I think I'd look towards 1400 metres now, he ultimately wants a mile but after that run I'm sure the speed will be out of him and he'll be crying out for 1400 metres."
Earlier on the card, Inner Flame overcame top-weight to land section one of the Class 4 Carpenter Handicap (1200m).
The Zoustar four-year-old was raised eight points in the ratings for a debut win last month but shrugged off that and the closing first-time starter Ping Hai Bravo (125lb) to take his career record to two wins from as many runs.
"I wasn't that concerned about the weight because he's improved at home and he's quite a solid unit," Whyte said. "It was just more about getting the right kind of run – if you're caught three-wide with 133 on a young horse it's detrimental and those sorts of circumstances could have cost him the race.
Alexis Badel, on a roll with the 13th win of his winter contract, drove the chestnut a length and a half clear at the line.
"He was given a beautiful ride, he got some lovely cover, he cut the corner and he picked up well; he's a thorough professional and I was happy to see him come to the races and improve on his effort first-up, which he needed to do to deliver the goods," Whyte said.
"The way he's improved and what he's shown me, how he's enjoying stepping out, he's going to handle himself and he's going to be competitive in the next grade. I'm just happy if they turn up and keep producing runs like him."
Chang's long-awaited brace
Michael Chang saddled his first double since 22 February, 2018 when Winning Together and Golden Four went back-to-back in races six and seven, and he went close to a hat-trick – and first treble since April 2014 – when Righteous Doctrine took second behind Bear Slam in race eight.
"It's nice to get that double and I think my horse performed well for second – he was beaten by the better horse so no excuse," Chang said.
Matthew Chadwick urged the willing Winning Together to success in section one of the Class 4 South Wall Handicap (1400m) to give the Chang runner his first win at the ninth ask.
The handler bagged his seventh victory of the campaign thanks to Blake Shinn delivering Golden Four on a well-timed run in section two of the South Wall Handicap (1400m).
Ferraris' fresh Slam
Bear Slam's (132lb) victory over Righteous Doctrine (122lb) came in the afternoon's trophy race, the Class 3 Lok Sin Tong 140th Anniversary Cup Handicap (1650m).
The Mizzen Mast five-year-old returned from more than two months without a run and made it two wins on the bounce over the course and distance, cruising off the turn under Joao Moreira and knuckling down for a strong run home.
"He's not very big and best kept fresh – he has a very good dirt pedigree," trainer David Ferraris said.
Tony Piccone's sound start to his first Hong Kong contract continued with a double. The Frenchman drove the Conghua-based Diamond Legend to a make-all win in the Class 5 Hau Wong Handicap (1600m), the second win of his stint and first for Tony Cruz, rewarding the handler's support at the sixth time of asking.
Piccone followed up with a powerful drive from deep, forging down the centre of the all-weather track's home straight on the pink-blinkered grey This One's For You to snare the Class 4 Nam Kok Handicap (1650m).
The latter win sealed a brace for trainer Lui who left the track with 27 wins on the board for the term, having earlier maintained his good form with Brilliant (118lb) in the opener, the Class 4 Carpenter Handicap (1200m). Derek Leung delivered the five-year-old on a strong closing run to edge out the well-regarded debutant Juneau Park (126lb).
Top-weight of 133lb failed to anchor the Tony Millard-trained Super Star, who landed his fifth win at his 10th start under a power-packed Silvestre de Sousa drive. The five-year-old Hong Kong International Sale graduate took the Class 3 Tak Ku Ling Handicap (1400m) by half a length.
Hong Kong racing continues at Happy Valley on Wednesday, 15 January.