British raiders Chigun and Hitchens claimed the main races on the 2,000 Guineas undercard at the Curragh.
Henry Cecil's Chigun was sent off the 11-8 favourite for the Abu Dhabi Stakes after being short-headed on her reappearance at Newmarket, and her task was eased here with market rival Caponata withdrawn due to being in-season.
Although slightly flat-footed at the halfway stage, Tom Queally soon had her on an even keel and she joined La Collina moving sweetly before drawing two and three-quarter lengths ahead at the line.
Queally said: "She did it well, I had a moment's worry at halfway on the ground but she has enough class and is going the right way.
I'm glad she won the way she did as I didn't want to throw the kitchen sink at her on this ground.
"There's scope to keep on improving. It's great to come home and ride a winner."
Asked if Chigun could reach Group One level, with former stablemate Chachamaideee winning last year's Matron Stakes at Leopardstown, Queally said: "It would be bold of me to say either way, but I think she's heading in that direction."
Hitchens repeated his Weatherbys Greenlands Stakes win of two years ago under a fine ride from Johnny Murtagh.
Trained in North Yorkshire by David Barron, the eight-year-old got a nice tow into the race as Leitir Mor set just a reasonable gallop on the rail.
The leader gave way a furlong out and Murtagh's mount (13-2) showed a nice turn of foot to put the Group Three event to bed, scoring by a neck from Reply.
Murtagh said: "He quickened through well, I thought he was always going to win.
"The owners were very happy with him today, they said he was in good form. He didn't like Newmarket (seventh in a handicap last time out), coming down the hill there and the firm ground didn't suit him."
As well as winning the Guineas with Magician, Aidan and Joseph O'Brien have a juvenile of possible Royal Ascot quality in Coach House, who took the the Cold Move European Breeders Fund Marble Hill Stakes with plenty in hand.
A son of Oasis Dream, Coach House, the 4-6 favourite, was winning for the second time from three starts.
Aidan O'Brien said: "We thought he was a nice horse. He won nicely first time.
"He's a lovely two-year-old. He has speed enough for five so he has all the options at Royal Ascot.
"Joseph said he showed lots of speed and that he even got there a bit early on him. He'll maybe get six or seven furlongs in time."
Owner John Magnier said: "Maybe the five-furlong Norfolk Stakes at Royal Ascot would be a race for him."
There was a 33-1 shock in the equisoftlive.com European Breeders Fund Fillies Maiden as Birdie collared O'Brien's 1-2 favourite Bye ByeBirdie.
Trainer Michael Halford said: "She has shown us plenty form the start at home. We do like her and she could go on to better things.
"We'll step her up into a Listed race at Naas (3 June). We wanted to get a nice introduction into her and she did well to win from where she was.
"Price doesn't matter to us, her owners are into breeding and we are not a punting yard."