Watch a full replay how the Andrew Balding-trained colt won the first Classic of the season in front of empty stands on the Rowley Mile
Pinatubo arrived unbeaten in six juvenile starts and boasting the highest two-year-old rating for 25 years - but he was only third as Kameko triumphed for Andrew Balding and champion jockey Oisin Murphy.
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 Aidan O'Brien's Wichita for the first Classic of the season.
However, while 10-1 shot Kameko found plenty in the final half-furlong, the 5-6 favourite Pinatubo had no more to give and it was left to Wichita to chase home the winner, beaten a neck. Pinatubo finished a further length adrift.
Murphy said: "I've never won a Classic in Britain and it means the absolute world to me. It's the stuff of dreams.
Balding, above, and Murphy, below, tell Nick Luck about Kameko's triumph
"It was a gutsy performance. He hardly blew a candle out afterwards - he must have a tremendous amount of ability.
"I'm thrilled, in those colours for Andrew Balding.
"I wanted to carry him (Balding) on my shoulders and swing him round and make him dizzy, but first of all I'm not big enough and strong enough to do that, and secondly there would have been a lot of bad press tomorrow morning!
"It obviously hasn't sunk in, there isn't the same atmosphere after the race - in fact there's no atmosphere - but it means just as much to me.
"I'm afraid to dream too big as often races don't work out as you'd planned or the result isn't the way you want it to go.
"This horse had trained very well without us doing anything silly on him at home and I was really pleased. I think really and truly Kameko is a very good horse."
Great scenes: A shattered Sheikh Fahad is slumped on the floor as Kameko carries his silks to victory in the Qipco 2000 Guineas
Balding said: "The form looked to stack up from the race at Newcastle and I'm just so grateful and thrilled to Sheikh Fahad and Qatar Racing for giving me a horse as good as this. I'm delighted for Oisin as well.
"He was doing his best work late on and this is his minimum. 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 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."
As befitting a Guineas winner, Kameko was promoted to Derby favouritism and his trainer is keen to head to Epsom on July 4.
Balding said: "To me it looks the obvious choice, there would be a stamina doubt but there's only one way to find out.
"We have to let David (Redvers, racing manager), Sheikh Fahad and Oisin all put in their opinions. I would be slightly reluctant to run him back at Ascot personally, so we will see what is on offer for him. He will certainly get a mile and a quarter, but there is a certain race over a mile and a half in July that would be quite appealing."
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."
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