Cachet made all down the Rowley Mile to give trainer George Boughey his first Classic success.
Remarkably, it was a second Classic of the weekend for rider Doyle – just 24 hours on from his maiden one aboard Coroebus in the 2000 Guineas.
Winner of the Nell Gwyn at the Craven meeting, the Highclere-owned daughter of Aclaim was sent off a 16-1 but led from the stalls opening and was never passed, despite the strong late challenge provided by the Ralph Beckett-trained Prosperous Voyage.
Try as she might, the latter could not get there, as Cachet answered every call to prevail by a neck, with Tuesday another length and three-quarters back in third for Aidan O’Brien and Frankie Dettori.
Doyle said: “I promised I wouldn’t get emotional today but that was incredible, wasn’t it?
“I rode her a couple of times last year, to a Group One place in the Fillies’ Mile, and we were talking about it beforehand, myself and George - she seems to be much stronger this year.
“That last half a furlong took forever and I was praying for the line, but she’s all guts, she loves this track.”
Doyle joins an exclusive club of riders who have completed the Guineas double. George Moore was first in 1967, followed by Lester Piggott (1970), Kieren Fallon (2005) and Ryan Moore (2015).
“It’s a very special day and I’ve got a lot of people to thank for getting here, but most notably the filly,” said Boughey to ITV Racing.
“She’s been a superstar since she walked into the yard. It was always going to be the question, that long final furlong, but she’s a star.
“It was a peach of a ride from James and she’s held on.”
Saturday’s first Classic of the season saw Yorkshire pair Perfect Power, trained by Richard Fahey, and Mark Johnston’s Royal Patronage fininish seventh and eighth respectively.
Both horses ran their race but never troubled the leaders, with Doyle’s mount beating stablemate and highly-fancied favourite Native Trail to give Godolphin and trainer Charlie Appleby a one-two, with O’Brien again taking third place with Luxembourg.
The Fitzdares Thirsk Hunt Cup had a surprise 66-1 winner as Redarna came flying down the outside with a perfectly-timed run by jockey Paul Mulrennan to deny David and Nicola Barron’s On A Session at their local track.
David O’Meara’s Pisanello finished third, with ante-post favourite Astro King back in ninth.
Rookie trainer Gemma Tutty is optimistic of claiming a first winner of her fledgling career when Little Jo runs at Beverley today.
Tutty is still waiting to get off the mark after taking over from her mother, Karen.
Little Jo was Gemma Tutty’s first runner as a trainer and came close to giving her a dream start, when second to Stately Home at Pontefract in April.
The eight-year-old gelding now bids to go one place better in the Brian Dixon Memorial Handicap at 3.51pm.
Tutty, who also saddles Fomo in the opener. said: “I rode him last season when he finished third behind Zihaam in this race, so he knows the track well.
“Pontefract is not too dissimilar to Beverley, so that last run also bodes well.”
Little Jo is one of 11 declared runners in the eight-and-a-half-furlong handicap, in which six-times Beverley scorer Zihaam and four-time winner on the Westwood, Poet’s Dawn, also run.