Carlingford Lough only made it into the field for the www.thetote.com Galway Plate at the 11th hour but his late inclusion paid dividends as he landed a gamble in the festival showpiece.
The John Kiely-trained seven-year-old was first reserve for the race after a full field of 22 horses were declared, but the withdrawal of fellow JP McManus-owned runner on account of the rain-softened ground allowed ante-post favourite Carlingford Lough to take his place in the race.
Partnered by Tony McCoy, Carlingford Lough was sent off the 7-2 market leader in one of the most competitive races of the Irish season but his supporters endured a nail-biting few minutes as the result looked far from certain some way out.
Mr Cracker set a testing early gallop and Fosters Cross and Tranquil Sea looked likely to be major players as the field approached the penultimate fence in the two-mile-six-furlong heat, with Carlingford Lough coming under pressure and seemingly having plenty to do.
However, McCoy's famed never-say-die will to win came into play on the long run for home as Carlingford Lough emerged from the pack to stake his claim with only around 100 yards to go.
Fellow McManus runner Quantitativeeasing was in front with the post in sight, but a late lunge from McCoy saw the favourite grab glory by a length and a half. Jacksonslady made it a one-two-three for McManus in third with Muirhead completing the frame in fourth.
Kiely said: "It's lovely to have horses for JP as he always has good ones. This horse had a few niggly problems and he (McManus) had patience with him all the time. He just came right and we trained him for this. You can't do it without the horse and he gave me the time to do what I wanted with him."
Kiely went on: "I was disappointed at first when he was only first reserve but I thought there'd be a few non-runners with the ground changing. Indeed, I didn't think the ground would be ideal for us either.
"I've won a Plate now and two (Galway) hurdles so it doesn't get much better than that - I can retire now. It'll depend on Mr (Frank) Berry as to where this horse goes next. He won't run in the winter anyway as the ground will be too soft."
McManus said: "I was watching my other runners for most of it but in the end AP lifted his fella home. It's just great to win it."
McCoy was quick to divert the praise to the horse, Kiely and McManus, saying: "The horse was very brave, he had a tendency to jump left which is not ideal around here and I had to keep dragging him back a bit. But he was brave, jumped the last two very well and stuck at it up the hill.
"It's great for the boss, and John Kiely has done a fantastic job with him. He won here last year, he had him spot on for today and there was no doubt the Galway Plate was his target from that day. You always give good rides when they win but he was very tough and genuine - anyone would have won on him. All credit should go to the trainer."