Frankie Dettori rode six consecutive winners at Santa Anita in California on Saturday evening.
The victories came at cumulative odds of more than 77,000-1.
Dettori famously rode a ‘Magnificent Seven’ of all winners on the card at Ascot in September 1996 at odds of over 25,000-1.
“I adore this place and to be able to say that I won six races on Derby day is beyond my wildest dreams,” said the 53-year-old Italian.
“I don’t know how to put it into words. Is it real? Am I dreaming? Is this really happening? It’s incredible. I just don’t know what to say.”
Dettori, who has ridden more than 3,300 career winners after being based in the UK for much of that time, delayed his retirement plans last year to ride on in the United States.
His six winners won at odds of 9-4, 6-1, 12-1, 9-2, 10-1 and 10-3.
The biggest success came in the Grade Two Santa Anita Oaks aboard 10-1 shot Nothing Like You.
Dettori had 11 rides in all, missing out on victory in his first race, before six consecutive wins. He was then second on 5-4 favourite Imagination in the Grade One Santa Anita Derby.
“He’s just a phenomenon,” Nothing Like You trainer Bob Baffert said of Dettori. “He is world-class and has brought his talent to every stage.”
The record for most wins for a jockey on one US card was set in 2005 when Eddie Castro won with nine of his 11 rides.
Santa Anita’s record for most victories by a jockey at one meeting is seven – for Laffit Pincay Jr in March 1987.
