A treble at Goodwood enabled Richard Hughes to draw level with Ryan Moore in the jockeys' championship race.
Defending champion Hughes started the day three winners adrift of his great rival, but wasted little time in reducing the deficit as he struck in the opening Alderbrook Handicap - restricted to professional National Hunt riders - on the Hughie Morrison-trained Aiyana (9/2 favourite).
It was a bit of a wait after that for the Hughes double, which came on Shadow Rock (5/1) for his boss Richard Hannon in the Irish EBF Maiden Stakes, making it 150 wins for the campaign.
The hat-trick was completed by Hannon's Yaakooum (6/1) in the Furniture Makes Handicap.
Dual title holder Hughes said: "If you want to be champion jockey this is what it is, it's pretty exhausting and mentally you have to be strong - if you have 12 good rides and don't have a winner. After a day like this it's great, you fly home and you're bouncing."
Roger Varian has confirmed Kingston Hill will not run again this season, ruling out a crack at Saturday's Qipco Champion Stakes at Ascot.
The St Leger hero still holds an entry in the 10-furlong feature but following a campaign that has also seen the Mastercraftsman colt finish second in the Derby and fourth in the Prix de l'Arc de Triomphe, Varian and owner Paul Smith feel Kingston Hill now deserves a winter break.
The trainer said: "Kingston Hill will not run again this season.
"He has done us proud this season, winning the St Leger, finishing second in the Derby and fourth in the Arc.
"He remains in training and we are looking forward to campaigning him in the big middle distance races next year."