Kameko powered to victory in the Qipco 2000 Guineas at Newmarket in a record time for the race under champion jockey Oisín Murphy, edging out Wichita by a neck, with red-hot favourite Pinatubo a length back in third.
All the attention was on Charlie Appleby's unbeaten Pinatubo after his brilliant unbeaten two-year-old season, but the 5-6 market leader could not find an extra gear when it mattered after looking to have every chance.
Last seen winning the Vertem Futurity Trophy on his final start last season, the Andrew Balding-trained Kameko (10-1) picked up where he left off last season and his superior stamina helped him to reel in Aidan O'Brien's Wichita (15-2) on the run to the line.
Kameko runs out of his shell!— Newmarket Racecourse (@NewmarketRace) June 6, 2020
An incredible victory in the QIPCO 2000 Guineas Stakes driven home by Champion Jockey @oismurphy for Andrew Balding who believes he is 'The best we've had at Kingsclere for many a year'. pic.twitter.com/u5PQ1hfklY
There was drama from the start as Kenzai Warrior nearly unshipped Jason Watson leaving the stalls, but all the main contenders soon settled in the pack as outsiders Persuasion and Juan Elcano cut out the early pace.
Kameko and Pinatubo were both perfectly poised to challenge and with a furlong to run it was between that pair and Wichita for the first British Classic of the season.
However, while Kameko had ample stamina to call on in the final half-furlong, Pinatubo had no more to give and it was left to Wichita to follow the winner home. Pinatubo finished a further length adrift, with Military March, also running in the colours of Godolphin, fourth.
Murphy, who hails from Killarney, said afterwards: "I've never won a Classic in Britain and it means the absolute world to me. It's the stuff of dreams.
"It was a gutsy performance. He hardly blew a candle out afterwards - he must have a tremendous amount of ability."
Kameko was predictably promoted to Derby favouritism and his trainer is keen to head to Epsom on 4 July.
"He was doing his best work late on and this is his minimum," Balding said.
"He will stay further than this. He has always looked smart and he always looked like he would be a better three-year-old as well.
"He was always travelling well and just when they quickened it looked like he was going to need a bit of a split and he didn't get the cleanest of runs. He went a little right-handed when he first let go and I was always confident he would get on top. It was only when he was past the line that I was happy though. That was the one we came here for and wanted."
Racing behind closed doors took no shine off the success for Balding, who added: "This is massive, as a Classic is a Classic whenever it is run. It has been a long time since I last won a Classic and it has been a long time since Kingsclere (his yard) has had a Guineas winner. It speaks volumes of the team at home. They have done an amazing job.
"It is huge and we are very grateful to everyone who has worked hard to get racing back on, and as I said a Guineas is a Guineas whenever it is run. I couldn't be happier.
"To me it (the Derby) looks the obvious choice, there would be a stamina doubt but there's only one way to find out."
Of Pinatubo, trainer Charlie Appleby said: "Pinatubo travelled well into the race there when he had Frankie's (Dettori) horse (Wichita) as his target, but when he made his move he got up to their girths and just didn't go any further forward.
"Obviously I'm disappointed as it's the first time the horse has been beaten in his career, but at least he hasn't fallen out of the back of the telly. He's had a normal blow after that and we'll take him home, but the first impression would be to take him to the St James's Palace Stakes."