Aidan O'Brien cemented his position as the leading trainer of his generation with an historic one-two in the Vodafone Derby at Epsom.

His High Chaparral battled to victory under Johnny Murtagh to give him a fifth success in the last seven British Classics, stretching back to last year's Derby-Oaks double with Galileo and Imagine.

But Ireland's third straight triumph in the race was agony for O'Brien's jockey Mick Kinane, who chose instead to ride stable-companion Hawk Wing, and for punters who sent that colt off 9-4 favourite.

The two runners from Ballydoyle had the £1.38m contest between them from some way out.

Murtagh, successful on Sinndar two years ago, made a move from the rear four furlongs from home on 7-2 chance High Chaparral and surged past Jamie Spencer on front-runner Moon Ballad a quarter of a mile from home.

He was immediately challenged by Hawk Wing but the Sagitta 2000 Guineas second's suspect stamina appeared to give out in the closing stages of the mile-and-a-half contest and he faded slightly in the final 100 yards to go down by two lengths at the line.

There was a remarkable 12 lengths back to the valiant 20-1 chance Moon Ballad Godolphin's second-string in third, with 100-1 outsider Jelani another length back in fourth.

Fight Your Corner fared the better of Mark Johnston's highly-touted pair in fifth, three places ahead of stablemate Bandari.

But Frankie Dettori's Derby jinx continued as he finished seventh on Naheef in the only big race to have eluded him.

And the event was touched by tragedy as Coshocton fractured a near-fore and fell in the final furlong and was destroyed.

His jockey Philip Robinson was taken to Epsom General Hospital as a precaution, though he was conscious and seemed not to have any serious injury.

O'Brien, the first trainer in living memory to saddle a one-two in Britain's premier Classic, described his top-class pair as ''two very, very serious colts'' and was delighted that owners Michael Tabor and Mrs John Magnier had allowed both to take their chance.

''With two real serious colts it is easy not to run them both and I must say well done for letting them both run,'' he said.

''We decided from a long way back that the Derby was the race for both of them and as the training went both got better and better.

''The race went great and the lads gave them two great rides, they didn't abuse them and both horses will be very well tomorrow, please God.''

But O'Brien, who is considering tilts at the Coral-Eclipse or Irish Derby for the pair who are now likely to be kept apart, played down his part in the triumph.

''It is well done to all the lads for the hard work keeping them well,'' he said. ''I have very little to do with it I only watch them every morning!

''We have a great team.''

But Tabor, a millionaire businessman whose reaction to High Chaparral's triumph was ''it can't get any better'', stressed: ''It is an amazing feat and Aidan is a tremendous trainer.''

And Murtagh added of O'Brien: ''He does more than sit in the car!

''He has a big part to play and he is a great man to ride for and he has shown what a trainer he is.

''He is a gentleman to ride for and leaves a lot up to the jockey he says 'you know best'.

''I am so delighted to be getting these outside rides the outside rides for Aidan O'Brien are as good as anybody's first strings.''

Murtagh, who is attached to John Oxx's yard, knew from some way out that High Chaparral would take some catching.

''He got a bit unbalanced coming down the hill but once I got to Jamie Spencer on the inside I was always picking up,'' he said.

''When my lad got to the front he responded in very game fashion.

''Mick got to within three parts of a length I could see him and I could hear him but I can't tell you what he was shouting!

''Once he didn't get past me quickly I thought we would be okay.

''A furlong down there was only going to be one winner, my lad was digging deep and so was I and I couldn't wait to see the line.''

Kinane had benefited from Pat Eddery's choice of Tenby to win the Derby on rejected stablemate Commander In Chief in 1993 and Murtagh said his weighing-room colleague would hold no grudges over getting it wrong this time.

''Mick was very lucky a few years ago when he won on a second-string,'' he said. ''So he knows what it is like to be on both sides of the fence."

Comparing his feelings with those after his win on Sinndar, Murtagh said: ''After the first one it was elation, today it is more emotion I feel very emotional.''

And the jockey hopes Ireland's sporting fortunes will continue on a high when the country's footballers play Saudi Arabia in the World Cup tomorrow.

''We have some good sports people in Ireland,'' he said. ''Our will to win is good, we are not afraid to work - I think Ireland will win 4-0!'