Rosallion led home a Richard Hannon one-two in the Irish 2000 Guineas, as the pair improved upon their second and third placings in the English equivalent.
The result was a reflection of the betting market prior to the race, with Rosallion justifying strong favouritism (10/11) and second choice River Tiber staying on well to finish third behind 6/1 shot Haatem.
Sean Levey settled Rosallion near the back of the field as Take Me To Church and Unquestionable set honest fractions from the front end. Stablemate Haatem, in the hands of Jamie Spencer, sat in third and it was he who hit the front first, taking the lead with a furlong and a half to run. Rosallion was switched to the outside to make his run and although the colt came with a strong charge, he found it difficult to get past his brave stablemate, recorded a Classic success by the narrowest of margin.
It was a first Irish 2000 Guineas victory for Richard Hannon, with his father, Richard Hannon Senior, taking the race three times – Tirol, Don't Forget Me and Canford Cliffs.
"I'm delighted, both of them have run a super race," said Hannon.
"Rosallion was a bit keen early and Haatem is such a brave horse, he's run such a lovely race and I've never known a horse to have as many supporters as he has. He probably didn't deserve to get beat but his day will come.
"Rosallion, I'm absolutely delighted with him, I couldn't be happier.
"He took a bit of time to pick them up. He's such a hyped horse and he's not going to please everybody. He proved he got the trip today and that was the pleasing thing.
"We'll go to the St James's Palace Stakes and try our best to beat the horse that beat us last time. It will be hard."
"I love the second horse, he's such a smashing horse and it's a pleasure to have him. I'm delighted with him," he added.
"Haatem has probably run the race of his life. This is a Guineas, they go on about how it's not a vintage Guineas but all the best horses had their chance and these two have run smashing races.
"I think he'll (Haatem) get further and will discuss it with the Sheikh (Abdullah Almalek Alsabah, owner) and the team and see where we go, but there are a lot of lovely days in him. I'd love to think they'll both stay in training next year, please!
"There is so much work that goes into these, there is a big team at home and I'm really pleased. These days are very rare and we're going to enjoy it.
"I'm delighted for Sean, for Sheikh Mohammed Obaid (Rosallion's owner) and Sheikh Abdullah will be delighted with his horse as he lost nothing in defeat, if anything he's probably earned more fans and his day will come."
Paddy Power reacted to the victory by shortening Rosallion from 3/1 to 7/4 for the Group 1 St James's Palace Stakes at Royal Ascot.