It's a familiar tune, but the switch to champion jockey Joao Moreira and some key race changes should see Lucky Profit back in the winner's photo after the Rotary Centenary Challenge Cup (1,200m) at Happy Valley tonight.

Either Moreira has a happy knack of getting on horses in the right circumstances or perhaps, the more likely explanation, they just take better advantage of the hand dealt for the Magic Man.

Danny Shum Chap-shing-trained Lucky Profit produced his career best winning in Class Five three runs back when Moreira rode him for the only previous time, camping just behind the speed over this course and distance from a similar draw to the one he has tonight.

The gelding produced a withering sprint that showed him as better than the cellar class in that win but things haven't panned out the same way with Derek Leung Ka-chun on board since. Drawn wide at Sha Tin, he didn't have a straightforward trip and went close behind Jolly Spring, before Leung had him in the right spot but didn't get a speed to suit when Lucky Profit finished off well into third last time.

Leung has done nothing wrong in the circumstances either run but Moreira just happens to be back on tonight with a good barrier as well as the likelihood of a solid pace, the two things the gelding has been missing.

Fierce-going Diamond Master should give Silvestre de Sousa's biceps a workout in the lead, and there are enough speedy followers to ensure a good tempo even if the Brazilian rider manages to work the oracle and settle the topweight.

Meanwhile, Moreira will rail up from midfield and a light weight will play its part as he descends on the front in the final 200m.

Tony Cruz-trained Mr Kool (Alvin Ng Ka-chun) produced his best effort yet last start at long odds from a wide draw. He could prove the danger tonight if he can produce something similar.