Charlie Appleby expects Pinatubo to prove a tough nut to crack when he puts his unbeaten record on the line in the Goffs Vincent O’Brien National Stakes at the Curragh today.

The Shamardal colt has been the star juvenile season of the season so far — winning each of his four starts, including stunning displays in the Chesham Stakes at Royal Ascot and the Vintage at Glorious Goodwood.

The form of the latter race in particular could hardly be working out better, with the placed horses — Positive and Lope Y Fernandez — both winning at Pattern level since.

Pinatubo tests the water at Group One level for the first time on Sunday, with Appleby bidding for back-to-back victories in the race following the success of Quorto 12 months ago.

“It looks a good race, but that’s what you expect when you step up to Group One level,” said the Newmarket trainer.

“Our horse is in good order. He looks well, and his form is working out well.

“He’s not doing anything different to what he was doing earlier in the summer. He’s not a brilliant workhorse, but he seems to produce his A-game in the afternoons.

“It’s his first start at Group One level. But his preparation has gone well, and I think he’s the one they’ve all got to beat.”

Aidan O’Brien has already saddled 11 winners of the National Stakes — and this year fires a four-pronged assault.

The Ballydoyle handler’s chief contender appears to be Armory who claimed his third win from four starts in the Futurity Stakes over this course and distance last month.

Armory is joined by Arizona — winner of the Coventry Stakes at Royal Ascot and subsequently fourth in the Prix Morny at Deauville — as well as outsiders Iberia and Toronto with O’Brien keen to provide competition for Pinatubo.

He said: “Armory is in good shape. Nobody wants to see easy races — they all want to see the good horses clash.

“You win some and lose some. You learn if you have to improve or if you are good enough.”

Jim Bolger ’s Geometrical the Mark Johnston-trained Monoski and Roman Turbo from Mick Halford’s yard are the other hopefuls.

The two-year-old fillies get their chance to shine in the Moyglare Stud Stakes, with Jessica Harrington’s Albigna the star attraction.

The daughter of Zoffany has been kept fresh for this Group One assignment since following up her maiden success at this track with victory in the Group Two Airlie Stud Stakes at the end of June.

“She’s all set for it, and you’d hope the step up to seven furlongs will suit her,” said Harrington.

“She’s not run for a while. I hope she’s the one to beat — but you never know, because there are one or two in there who have just won maidens.

“We’ll wait and see what happens on the day.”

Albigna’s biggest threat appears to be Roger Varian’s British raider Daahyeh — winner of the Albany Stakes at Royal Ascot before being touched off by Raffle Prize in the Duchess of Cambridge Stakes at Newmarket.

“I am hopeful of her staying the seven furlongs and very happy with her condition,” Varian told irishchampionsweekend.ie.

“The Curragh should be no problem, but we have to find out about the seven furlongs — and it is a stiff seven furlongs there.

“That said, she is a similar type of filly to Cursory Glance, who won the Moyglare for us in 2014, having also won the Albany.

“She boasts some of the best juvenile filly form and has strong credentials in the race, even if it is always a hot race at the Curragh.”

James Tate’s Under The Stars is another British-trained contender — while Aidan O’Brien runs Love Precious Moments So Wonderful and Tango

The Ger Lyons-trained Soul Search and Bolger’s unraced filly Assurance complete the nine-strong field.

The first of four Group Ones on a fantastic afternoon is the Derrinstown Stud Flying Five Stakes.

The likely favourite for the five-furlong sprint is Eddie Lynam’s Soffia who makes her first appearance since a brilliant display in the Sapphire Stakes here in July.

Lynam is pleased connections of Nunthorpe hero Battaash decided against a trip to Ireland, but is taking nothing for granted.

He said: “This has been the plan, and it certainly helps we don’t have to take on Battaash. That said, the second (Soldier’s Call), third (So Perfect) and fourth (Mabs Cross) from the Nunthorpe are there.

“It’s going to be tough, but I’d be very happy with her.”

Michael Dods is hoping Mabs Cross can get back on the winning trail, having finished behind Battaash on her last three starts.

“We’d already decided we were going to the Curragh before news came out that Battaash was going straight to France for the Abbaye, but obviously I’m quite happy Battaash isn’t going to turn up,” said the Darlington-based trainer.

“I think the track will suit her, and we want a nice pace to aim at.

“The Irish sprinters do seem stronger over six furlongs — but it’s still a Group One race, and they take a bit of winning. We’re pleased with her anyhow.

“We don’t need soft ground. It was very quick ground for the Nunthorpe — I just hope it’s not that quick.”

Mick Appleby ’s Caspian Prince James Tate’s Invincible Army Karl Burke’s True Mason and Martyn Meade’s Houtzen also represent Britain.

The latter — formerly trained in Australia — made an encouraging start for her new trainer when second to Battaash at Goodwood.

“Obviously she’s had to adjust to a different training routine over here,” said Meade.

“In Australia they train them at the track, but she’s actually probably well-suited to how we train here. She’s not really a typical sprinter — she’s pretty laid-back.

“Her run at Goodwood was excellent. I think the ground and track will be fine for her at the Curragh, and she’ll then likely go to the Prix de l’Abbaye.”