Success Days caused a 10-1 upset when making virtually all of the running to land the Kilfrush Stud Royal Whip Stakes at the Curragh.
The race looked set to be a clash between Ascot Champion Stakes hero Fascinating Rock and Derby runner-up US Army Ranger, but Ken Condon's charge did not read the script, setting the gallop under Shane Foley and pulling into a clear lead entering the home straight.
The Dermot Weld-trained Fascinating Rock (2-1) was the closest pursuer in the final furlong, but he just could not bridge the gap, which remained three-quarters of a length at the line.
Aidan O'Brien's US Army Ranger, who was sent off the even-money favourite, was held up in the rear of the field before making smooth headway on the home turn but his run flattened out after that in fourth.
Churchill (1-4 favourite) confirmed himself a colt of huge potential when coming out on top in the Galileo European Breeders Fund Futurity Stakes.
Aidan O'Brien's Royal Ascot winner was already at the forefront of the betting for next year's Investec Derby after following up in a Group Three at Leopardstown, and travelled well behind leader Arcada in the early stages of the race.
After Seamie Heffernan angled the favourite out to lead over a furlong out the result was hardly in doubt, as he fended off the challenge of Radio Silence by two lengths, looking better the further he went.
Rhododendron (11-8 favourite) gave Aidan O'Brien his 11th win in the Breast Cancer Research Debutante Stakes when holding stablemate Hydrangea (10-1) in the Group Two at the Curragh.
After opening her account at the second attempt in a Goodwood maiden last month, the daughter of Galileo took the big step up in grade in her stride.
Oh Grace set the early pace before Hydrangea set sail for home three furlongs out, with Intricately (14-1) looking dangerous.
Seamie Heffernan brought Rhododendron with a strong run in the centre of the course to hit the front a furlong out.
It was not quite all over, though, as Hydrangea rallied for Padraig Beggy and was only a head down at the line to give O'Brien a one-two.
A length and a quarter back in third was Intricately, trained by O'Brien's son Joseph and ridden by another son, Donnacha.
