Illinois got Arc weekend off to a flying start for Aidan O’Brien and Ryan Moore with a determined victory in the Qatar Prix Chaudenay at ParisLongchamp.

Having filled the runner-up spot in the Grand Prix de Paris, the Great Voltigeur and the St Leger since his Royal Ascot victory in the Queen’s Vase, the Galileo colt was a warm order to strike Group Two gold on his return to the Bois de Boulogne and was soon bowling along at the head of affairs.

Moore had to get to work from the home turn and the 4-9 favourite looked at the mercy of Trafalgar Square after being joined and briefly passed by his French rival, but Illinois gritted his teeth to keep himself in the fight and battled back to score by a widening two lengths at the line.

“I’m delighted, he’s a lovely horse and straightforward and stays very well. He’s lazy but finds plenty and Ryan said he’d have no problem coming back in trip if he needs to,” said O’Brien.

“In an ideal world you’d prefer to get a lead, but we’re very happy as it was a lovely race to come to after he got beat in the Leger.

“He should be a lovely four-year-old. I was obviously concerned when the other horse came to him, but knowing him he finds loads and Ryan gave him a great ride – that’s Ryan all over, isn’t it?”

Paddy Power cut Illinois to 8-1 from 10-1 for the Qipco British Champions Long Distance Cup, but he appears unlikely to turn up at Ascot in a fortnight’s time.

O’Brien added: “That will probably be it for him for this year, I’d imagine. It’s a nice, long winter and he’ll be ready to start early in the spring. Ryan said he could start in Dubai or anywhere.”

After doubling up with the remarkable Kyprios in the Prix du Cadran, O’Brien and Moore made it a treble on the card with Mount Kilimanjaro justifying 9-4 favouritism in the €260,000 Arqana Series – Haras de Bouquetot Criterium d’Automne.

Although the son of Siyouni could only finish fifth and third respectively on his first two starts, the form of both has worked out well, with the winner of his Leopardstown debut Scorthy Champ going on to win the National Stakes and Field Of Gold, who Mount Kilimanjaro was placed behind when last seen in action at Newmarket in July, following up in the Solario at Sandown.

With Moore again positive from the off, Mount Kilimanjaro dug deep when challenged and his trainer believes there will be even more to come next season.

“He had a couple of nice runs early and the maiden he ran in Newmarket worked out very well – I think the winner (Field Of Gold) runs in the Lagardere here tomorrow,” said O’Brien.

“Our fella will be a lovely middle-distance horse next year, a mile or a mile-and-a-quarter horse. He’d be one for one of the trials in the spring and he’s big, too.

“He’d be working nicely and Ryan gave him an uncomplicated ride. We could have a look at one of the Group Ones in Saint-Cloud, but we’ll see.”