Mr Stunning rolled back the years to take the Chairman's Sprint Prize at Sha Tin.
Much of the pre-race attention had surrounded Aethero and his supporters enjoyed the perfect beginning, as the John Moore-trained favourite was smartly away from the stalls to lead the Group One field.
But it became clear soon after entering the straight that all might not be well and he was eased and virtually pulled up by Zac Purton from the 300-metre mark.
Market rival Hot King Prawn had every chance, as did Voyage Warrior, who had beaten the big two last time out, but ultimately it was the seven-year-old Mr Stunning who burst through under Karis Teeton.
Twice the winner of the Hong Kong Sprint at the International meeting, the Frankie Lor-trained gelding had three-quarters of a length in hand over Big Time Baby, who edged Aethero's stablemate Thanks Forever for second.
Lor said: "He's a seven-year-old now but this season, for me, he's always been very close, unfortunately last season he had that shoulder problem but now everything's good.
"Because of the hairline fracture he had, I can't push him too hard, especially as he is an older horse, that's why this time I didn't trial him before this race - we just freshened him up.
"We planned this to be his last run but let me talk to the owner and we will decide and see what he thinks about the horse - he was my first Group One winner, I'm very happy for him."
Moore said of Aethero, who was last across the line and was found to have bled: "It's disappointing but we'll make sure he's all right and then I'll sit down with the owner and we'll have to discuss the best thing for him."
He added of Thanks Forever: "He had to make up ground, he was in front at the 100 (metres) and he just folded.
"I think if he'd drawn a gate and laid up a little closer he could have won. He had to make it up from the 400 (metres)."