Jet Setting inflicted a shock defeat on Minding in the Tattersalls Irish 1,000 Guineas at the Curragh.
The Aidan O'Brien-trained Minding was a red-hot 4-11 favourite following her runaway victory in the 1000 Guineas at Newmarket three weeks ago.
Jet Setting (9-1), trained by Adrian Keatley, was back in ninth at Newmarket, but emphatically reversed the form under Shane Foley to claim Classic glory by a head, with Now Or Never 10 lengths back in third.
The winner was supplemented for the race on Monday at a cost of 30,000 euro.
"It's a dream come true," said Foley.
"She's a tough little filly and the ground came right for her - s he ran a blinder at Newmarket but it was too fast for her.
"Soft ground and a stiff mile was ideal for her."
Minding was originally scheduled to bypass the Curragh and head straight to the Investec Oaks at Epsom, but was drafted in at the last minute after stable companion Ballydoyle, the runner-up at Newmarket, returned unsatisfactory blood tests on Friday.
Everything appeared to be going according to plan for the three-times Group One winner for much of the contest, with stable companion Pretty Perfect and Jet Setting giving her a nice lead into the straight.
However, Jet Setting found another gear passing the four-furlong marker and it was soon obvious Minding would have her work cut out to reel her in.
Ryan Moore went for everything inside the final furlong and Minding responded to set up a grandstand finish.
The pair had raced clear of the field as the post loomed large and while Minding appeared to be getting the better of the argument at one stage, Jet Setting would not be denied.
Jet Setting holds an entry in the Coronation Stakes at Royal Ascot, but Keatley is keen to assess conditions in Berkshire before making a firm commitment.
He said: "It's a dream. I was just hoping at the finish that she stayed where she was.
"I'm delighted for the owners and everyone in the yard.
"Hopefully this will help us get bigger, better and more competitive so we don't have to keep going to Ayr every Monday!
"I don't know what's next. I didn't look beyond this. She's entered in Ascot but whether she goes or not I don't know.
"When the rain was forecast we said we'd have a go here and, luckily enough for the lads, it worked out as it was a big call to supplement her again.
"She did something similar to what she did in Leopardstown (when successful in a Guineas trial). She likes being in front and having daylight around her.
"She probably wouldn't go to Ascot if it was very fast but if there was a bit of ease she might. We'll consider it and have a look.
"If she's that good at a mile why would we try and change anything?"
Famous Classic strike for Awtaad and Kevin Prendergast
Awtaad justified Kevin Prendergast's high opinion of him when winning the Tattersalls Irish 2,000 Guineas at the Curragh.
It is 40 years since Prendergast last saddled the winner of the colts' Classic with Northern Treasure and it was well worth the wait for the octogenarian handler.
Chris Hayes was always sitting pretty on the Sheikh Hamdan Al Maktoum-owned son of Cape Cross and kicked for home about two furlongs out.
Awtaad (9-2) galloped all the way to the line to beat Qipco 2000 Guineas hero Galileo Gold (5-4 favourite) - who had to show plenty of determination when seeking a gap on the rail - with Blue De Vega third.
Hayes said: "Unbelievable. I didn't sleep for a week. He's been flying and we've always held him in high regard.
"Mr Prendergast gave me no instructions, except don't get there too soon, which I did! I had no option. I saw Frankie (Dettori on Galileo Gold) was in a bit of bother.
"I just wanted to make it as hard as I could for him, but it wouldn't have made any difference. I'd have loved to have a lead a bit longer.
"Hopefully, it's Royal Ascot now."
He added: "He's the best horse I've ever ridden.
"This means a lot to me and Mr Prendergast has been so good to me."
Coral slashed Awtaad to 16-1 (from 50-1) for Epsom, with BoyleSports going 5-1 about the St James's Palace Stakes at Royal Ascot.
Royal Ascot set to be next stop for classy Caravaggio
Royal Ascot is firmly on the agenda for Caravaggio after he came with a rattling run to maintain his unbeaten record in the Cold Move EBF Marble Hill Stakes at the Curragh.
The pace-setting Mister Trader held a good lead with a furlong to go but once Ryan Moore rousted the Aidan O'Brien-trained colt, Caravaggio set out his business in pleasing style.
The highly-regarded 4-7 favourite, who made a winning debut at Dundalk five weeks ago, asserted in the last half-furlong to win cosily by two and a quarter lengths.
Mister Trader was four and a quarter lengths clear of Ambiguity in third.
O'Brien said: "He's not a soft ground horse, so I'm very happy with that. That's his first run on grass and he will have learned a lot today. Ryan gave him a lovely ride.
"To break a minute up here on fast ground is very good so to do what he did today on soft ground (1m 02.22sec), getting close to heavy, is a serious time. It worked out lovely, he got a lead, which we were worried that he might not, and if you see when he changed (legs) he went halfway across the track.
“That's a real sign of greenness.
"We'll have to decide which race to go for at Royal Ascot (the Coventry or the Norfolk), but I think he will get six furlongs."