Kew Gardens led home a one-two-three for Aidan O’Brien as he dominated the Queen’s Vase to gain a first winner of the week at Royal Ascot.
Only ninth in the Derby when last seen, the 100-30 winner was the choice of Ryan Moore and ultimately ran out a decisive victor.
Despite racing over the extended mile and three-quarters distance for the first time, Nelson set a very stiff gallop at the head of affairs.
Turning into the straight he was still in front, but the pack was closing, including Frankie Dettori on Stream Of Stars.
It soon turned into a Ballydoyle benefit, though, with Kew Gardens sprinting clear and Southern France coming from almost last to beat Nelson for second, some four and a half lengths away.
Kew Gardens is now as low as 10-1 for the St Leger, a race connections appear keen to go for.
Michael Tabor, co-owner of the winner, said: “We’ve always thought he’s a nice horse, really made for this race.
“Obviously he needs a trip, so the St Leger, why not?”
O’Brien said: “We always thought he’d stay. He loves fast ground. He was a little bit disappointing in Epsom, but we’ve been very happy since then.
“He can do a lot of things. He can go back to the Irish Derby. He can have a little break and be trained for the Leger. He’s a lot of options.
“The Leger is a long way away, but in the autumn that would be a lovely race for him.”
He added: “You’d be very happy with them, and they are all horses for the future really.”
Best of the rest in fourth was the John Gosden-trained Almoghared, who could also be Leger-bound at Doncaster in September.
Angus Gold, racing manager to Sheikh Hamdan Al Maktoum, said: “I thought it was a huge run from such an inexperienced horse.
“He was a big baby six weeks ago and has come a very long way. He has got a fantastic attitude and temperament, which all help him. We really feel he is a work in progress.
“Two weeks ago we would have laughed if you’d said we would come with a run on the outside and nearly win a Queen’s Vase. He looked for a moment like he was going to be a threat. It was really encouraging.
“If he continues to improve we would certainly have to think about something along the lines of the St Leger.”