Newmarket: Iron Duke shows his mettle to nail fifth Group One success

Some horses are not so much foaled as hewn, and Duke Of Marmalade is among their number. Even his trainer, Aidan O'Brien, stands in awe of the four-year-old's staggering resilience and durability, qualities that would rank him high on the Mohs scale. "They always say that tough horses are made of stone, don't they?" said the Irishman. "I can tell you that this one was carved from something much, much harder. I can't believe he's just flesh and blood."

Duke Of Marmalade and Johnny Murtagh had just notched an 18th Group One success of the year for the trainer in the Judd-monte International at Newmarket. The ten-furlong contest, rerouted after the week's cancellation of waterlogged York, also featured the return to action of Derby hero New Approach, but the projected inter-generation showdown neither materialised, nor threatened to.

New Approach, running for the first time since Epsom, was far too keen early on and had little dash left when Kevin Manning asked him for an effort at the sharp end of the race. It was left to Phoenix Tower to put it up to Duke Of Marmalade, who had taken over from his pacemaker Red Rock Canyon fully three furlongs out, but though his challenge was gallant it was always unavailing.

One slap from Murtagh and the Duke, known to run lazily once he hits the front, stretched his stride and took the £142,000 prize by a cosy three-quarters of a length. "Nothing fazes this lad," said his rider. "I knew he'd pull out plenty. He is truly a remarkable horse."

It was Duke Of Marmalade's fifth successive Group One success since April, equalling the record in a season of two other notable hard men, Giant's Causeway and Rock Of Gibraltar. Both were trained by O'Brien, whose latest star will get his chance for a sixth elite success in the Irish Champion Stakes at Leopardstown on Saturday week.

Yesterday's achievement was especially commendable given its build-up. On Tuesday Duke Of Marmalade spent nearly 11 hours on the road and in the air in his fruitless journey to the Knavesmire. But a strapping constitution – his fighting weight is 540 kilos – and level head saw him through a journey which might have flattened a lesser athlete.

"He has such physical and mental strength and soundness," added O'Brien. "He never worries about anything and if you take the tack off him, he'd just stand there until you told him to move. He never wastes any energy at all."

It was Phoenix Tower's second defeat of the season by Duke Of Marmalade, and he will not lock horns with that adversary again. But the Duke will face a rematch with New Approach, two and a half lengths third, at Leopardstown next month. "Beaten, but definitely not battered," said the chestnut's trainer, Jim Bolger. "He ran a good race and is on the way back. I imagine you'll see a different horse in two weeks' time."

O'Brien's quest for Group One glory has become a defining narrative of this season; another is Sir Michael Stoute's for a first St Leger triumph. Yesterday at Goodwood his Patkai went into the Great Voltigeur Stakes as hot favourite for the Classic at Doncaster in 20 days' time and came out of it removed from the market, having failed to cope with the step up in class that the Group Two contest presented.

He has been replaced at the top of most bookmakers' lists by yesterday's all-the-way winner Centennial, who would have to be supplemented for the big race at a cost of £45,000. "My fault," said the Dalakhani colt's trainer, John Gosden. "I should have entered him. But there's enough money in the pot now if we decide to go."