It may not have been the result that the majority of the 17,000-strong Leopardstown crowd anticipated, but racing was the real winner as Fantastic Light got the better of Galileo in a truly epic duel for the 'Ireland The Food Island' Irish Champion Stakes.
Each camp had employed a pacemaker to ensure a true-run race, but it soon became clear that Godolphin's hare Give The Slip would not be attempting to match strides with the tearaway Ice Dancer up front.
A change of tactics for Fantastic Light saw him sit in third, just ahead of the red-hot favourite, and by the time the field reached the turn-in the anticipated struggle was guaranteed as the big two went on.
Frankie Dettori had got first run on the inside, and although Galileo initially seemed to be travelling the better it soon became apparent that he had a real battle on his hands.
For the final furlong-and-a-half the pair were asked and responded to every possible question by their riders, and at the line it was the current World Champion who had prevailed by a head.
The decision by Godolphin to precede Galileo was a late one, according to their jubilant racing manager Simon Crisford. 'Sheikh Mohammed and Sheikh Maktoum (Al Maktoum) felt we should put it up to him this time,' he said.
'Visually, that was really special to watch - the horse has fulfilled all our expectations and is an all-round superstar,' he went on.
Trainer Saeed Bin Suroor confirmed that the Breeders Cup Classic is now top of Fantastic Light's agenda, and with that comes the mouth-watering prospect of another clash with his great rival.
The Ballydoyle team must now decide whether to go for the QEII Stakes at Ascot in the meantime, but O'Brien said : 'I don't see any reason why he shouldn't go to America.
'It was a great race to watch, but you can't win them all. The way things panned out we probably should have been handier, but I thought Give The Slip would follow Ice Dancer. The winner did it very well, and the lads planned it brilliantly tactically.'
O'Brien and Kinane had earlier enjoyed the perfect start to the big day when combining for an opening-race double with Della Francesca and Ishiguru.
Ishiguru (9/4-7/2) belied an apparent lack of market confidence when just holding the late thrust of Indian Spark in the Group 3 Miller Flying Five.
As expected, the well-supported Repertory set a scorching pace here, but he was treading water a furlong out and faded into third as the Ballydoyle runner went on to score by a rapidly-diminishing head.
The Prix de l'Abbaye at Longchamp on Arc day is now the objective for Ishiguru, for whom a fast-run five furlongs is ideal, according to O'Brien.
Della Francesca (4/9-2/5f) showed the anticipated improvement from his York debut effort when comfortably justifying favouritism in the opening two year-old maiden.
The Danzig colt was always prominent in the 6f event, won last year by stable-mate King Charlemagne, and only needed to be pushed out by Mick Kinane for a cosy 2 1/2 length verdict over Fashion Guide.
'He's a fine big horse, and learned a huge amount from his debut at York,' said O'Brien, who will now consider the valuable Tattersalls Somerville Stakes at Newmarket for his next outing.
Muakaad, sixth in the Arlington Million three weeks ago, returned to winning ways with a good effort in the Listed Kilternan Stakes.
After watching the four year-old see off the staying-on Muakaad by 2 1/2 lengths, trainer Dermot Weld said :
'Things just didn't go his way in America, but he came out of the race well. I'll have to speak to Sheikh Hamdan (Al Maktoum) to see where he goes next.'
Montpelier Street had to settle for the runner-up spot in a valuable handicap for the second week in a row when overhauled close home by D'Anjou in the #100,000 Tote Exacta Handicap.
Tom Cooper's charge, touched off by Osprey Ridge in last weekend's Cambridgeshire at the Curragh, appeared to have poached a decisive advantage turning-in but was again cruelly collared in the dying strides.
D'Anjou was almost retired last season after encountering what John Oxx described as 'a few little problems', but has really come good in the last month or so and could now step up to Group 3 company for the Concorde Stakes at Tipperary.
Clever Consul (Tadgh O'Shea) followed up his win at Downpatrick when pulling out all the stops to deny Direct Bearing in another great finish to the 2m handicap.
The judge was busy again following the 1m1f handicap, with Eddie Lynam's Sweet Surrender getting home by the minimum margin in a blanket finish from Right Job and the fast-finishing Abaco, who was subsequently disqualified.
14/1 shot Solid Gold, the outsider of Jim Bolger's two runners, ran out a decisive winner of the concluding nursery under Sean Cleary.
