Winter won the 1,000 Guineas at Newmarket to give trainer Aidan O’Brien a third double in the Guineas.
O’Brien won Saturday’s 2,000 Guineas with Churchill and also won both Classics in 2005 and 2012.
Winter, ridden by Wayne Lordan, denied Ryan Moore a Guineas double as stablemate and 9-4 favourite Rhododendron was second, with Frankie Dettori third on Daban.
O’Brien now has four wins in the race and 27 British Classics wins.
The Irish trainer, who has won 13 of the last 27 British Classics, fielded three runners in a bid to win the fillies’ Classic, with Hydrangea his other runner.
While Rhododendron endured a troubled passage, Winter stayed out of trouble wide of the field.
Lordan guided the 9-1 shot to the front entering the final furlong and held off the challenge of Rhododendron, who came home strongly.
“She travelled quite well,” said Lordan. “I went forward quite early because she’s a filly that gallops and I knew the track would suit her.
“This means a lot. I’m very grateful to Aidan for letting me keep the ride on the filly.”
BBC horse racing correspondent Cornelius Lysaght
Punters love it, purists aren’t quite so sure, but what everyone can agree on about this near big-race monopoly is that the Aidan O’Brien winner machine is beautifully oiled and working like clockwork.
Here Rhododendron was luckless, not helped as O’Brien’s third runner Hydrangea faded, but Winter won well enough that it’s uncertain whether it had made the difference.
Coolmore partner Michael Tabor said he was delighted but “this game can turn very quickly”, although it has to be said that this has been the situation since high summer last year and shows no sign of changing.