Double reverse for O’Brien and Fallon
The highly-rated Grand Central was held by Alayan in a tactical race for the Leopardstown 2,000 Guineas Trial, while Almighty was only fourth to Bobs Pride in the P.W. McGrath Memorial Ballysax Stakes.
Alayan made all the running to floor hot-pot Grand Central with Michael Kinane dictating affairs on the Aga Khan's colt.
Fallon was content to settle his charge on the rails, last of the four runners until trying to mount a challenge in the final furlong on the 8-15 favourite.
Alayan (9-2), trained by John Oxx, found more to win by three and a half lengths.
Oxx said: "He's a tough little horse, very genuine, although there's not a lot of him.
"Michael liked him a lot last year and he was keen on running him here today.
"I've always thought of him as a fast-ground mile and a quarter horse and I think he'll get a mile and a half in time.
"Before today we had no Classic aspirations for him. We'll have to think about a Guineas now. But I don't know if he's entered.
"He's in the Derrinstown Derby Trial here which would look an obvious race.
"We'll have to go home and think about it. He's obviously better than we all thought."
Fallon said: "It's great when you are allowed to dictate and when they don't take you on, especially on this ground and a course like this.
"It's very hard to get to the horse in the lead. Mick stole the race but in fairness you can't take anything away from his horse.
"He was impressive. He's won well and I don't think anything would have beaten him today.
"My horse will improve and he wants better ground. Hopefully, the next day we will have a different result."
Following his surprise defeat, Grand Central was pushed out to 50-1 from 8-1 for the UltimatePoker.com 2000 Guineas with Irish bookmakers Cashmans.
Oxx and Kinane completed a 19-1 double when 11-4 joint-favourite Icklingham took the www.leopardstown.com Handicap by a length and a half from Saintly Rachel.
Almighty, who holds entries in the Dante Stakes and Vodafone Derby, was most disappointing behind the Dermot Weld-trained Bobs Pride and is now 33-1 from 16-1 for the premier Classic with Coral.
The even-money shot never got in a blow as the well-backed 5-4 second-favourite headed long-time leader Mister Hight a furlong out in the hands of Pat Smullen.
He went on to land the Group Three race over 10 furlongs by two and a half lengths over Mister Hight, from the Grand National-winning stable of Willie Mullins.
Of Almighty, Fallon said: "He's a horse I've liked at home. He's been doing everything fine. It was disappointing to see him beat fourth of five and to get beat like he did. He was off the bridle a long way out.
"He's a horse that improved a lot for his first ever run and hopefully he'll go and do the same this year and go on to better things."
O'Brien and Fallon did, however, land a 13-1 double with Emerald Cat (3-1) and Virginia Waters (5-2).
The latter ran out an easy winner of the Dimitrova 1,000 Guineas Trial Stakes to stake a claim for the UltimatePoker.com 1000 Guineas at Newmarket.
Totesport go 16-1 from 33-1 about her Classic chance, while she is 25-1 from 66s with Ladbrokes.
Virginia Waters came with a sweeping run on the outside and powered to a smooth three-length victory from Sweet Treat in the Group Three contest over seven furlongs.
O'Brien said: "She's won very snug. Kieren rode her work and loved her and got a good idea of how to ride her.
"On breeding you wouldn't think she'd like soft ground. All she has been doing at home is cantering so we did not know if she was really ready.
"The ground here is definitely better than it is at home.
"She's a possibility for Newmarket. Kieren says she's ready to step up now."
Emerald Cat made a winning debut in the Irish Stallion Farms EBF Maiden, beating Qassas by two lengths.
"You'd imagine he'd prefer fast ground on breeding. He's a nice horse with a change of gear," added O'Brien.
"He's a fast learner and could be ready to step up to a good race next."
