Odds-on favourite Minding stayed on strongly to win the Oaks and complete a Classic double at Epsom on Friday.
The three-year-old filly was surprisingly beaten by Jet Setting in the Irish 1,000 Guineas less than a fortnight ago, but responded with a classy victory on the Downs in Surrey.
Minding went off as the 10/11 market leader and was guided out of trouble by Ryan Moore to beat 12-1 shot Architecture by almost two lengths, becoming the first filly for 14 years to pull off the 1,000 Guineas-Oaks double.
Questions had been raised over whether Minding would stay on, but the one mile four furlong trip proved to be no problem as the Ballydoyle heroine claimed another Group One triumph a month after winning the 1,000 Guineas at Newmarket.
Minding returns. What performance that was, no wonder the lad was all smiles! pic.twitter.com/MhbSoywTqL-- EpsomDownsRacecourse (@EpsomRacecourse) 3 June 2016
And now back to the stables for Investec Oaks heroine Minding. Probably looking forward to a bite to eat pic.twitter.com/nme9DKZrt8-- EpsomDownsRacecourse (@EpsomRacecourse) 3 June 2016
Minding's victory was a sixth for trainer Aidan O'Brien in the famous race and a second for prolific jockey Moore.
It was not all plain sailing for the standout horse in the field of nine, as Moore was boxed in at the turn for home but he navigated Minding out wide and the favourite bolted past the Hugo Palmer-trained Architecture, under Frankie Dettori, a furlong from home to win in impressive fashion.
Moore told Channel 4 Racing: "There was nowhere to go [just after the turn for home], but a good filly got me out of trouble. Her class got her out of trouble."
Harlequeen, ridden by Silvestre de Sousa and trained by Mick Channon, came home in third.