Andrew Balding's Kameko stunned unbeaten favourite Pinatubo to win the 2,000 Guineas at Newmarket, the first British Classic of the year.
Oisin Murphy guided the 10-1 shot through the centre on good to firm ground for a famous victory by a neck.
Kameko's win set a new track record at 1min 34.72 secs, beating Mister Baileys's time in 1994.
The Aidan O'Brien-trained Wichita (15-2), ridden by Frankie Dettori, took second.
Pinatubo (5-6) was on the inside rail but finished third in a field of 15, one and a quarter lengths back.
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Kameko, beaten by a neck over the same course and distance last September, won by three and a quarter lengths last time out in November.
Pinatubo beat Arizona by two lengths on soft ground over seven furlongs in the Dewhurst Stakes at Newmarket last time out in October, when Wichita was third.
But on a blustery, showery day behind closed doors at the Suffolk track, the favourite was unable to find an extra gear in his seventh race.
Celebrating his first British Classic, Murphy said: "It means the absolute world to me. It's the stuff of dreams.
"Around four furlongs he got a little bit lost but he came home really well.
"It was a gutsy performance. He hardly blew a candle out afterwards - he must have a tremendous amount of ability."
Having given Balding a first Guineas triumph, Kameko is now favourite for the Derby at Epsom on 4 July.
Balding, who won the Oaks with Casual Look in 2003, said: "To me it looks the obvious choice. There would be a stamina doubt but there's only one way to find out."
Pinatubo's trainer Charlie Appleby, who won the Group One Coronation Cup with Ghaiyyath on Friday, said: "Pinatubo travelled well into the race when he had Frankie's horse as his target, but when he made his move he got up to their girths and just didn't go any further forward."