George Baker steered Harbour Law to victory in the St Leger as Laura Mongan becomes the first woman to train a winner in the Grade One race.
Baker came past Ventura Storm and Housesofparliament to take victory on the outside after favourite Idaho had unseated Seamie Heffernan following a slip with over three furlongs to run.
"We saw him in the paddock and we couldn't believe how well he looked," Mongan said.
"It's all a bit surreal at the moment - a lot of screaming - but this is brilliant.
"George has ridden the horse all the time. He knows exactly what to do and we left it all in his hands today as we knew he would know what to do."
Mick Cornwell, who owns the horse with wife Jackie, said: "We were praying for rain on the way up and when we got about 15 miles on the track it stopped and we thought that might be that but he was the best horse on the day.
"We'll sit down now and make a plan. He's progressed as the year has gone on and I think he will progress again next year.
"Between myself and Jackie, we've been involved in racing for more than 20 years, we have a pre-training yard in Whitcombe, but we've never experienced anything like this."
Heffernan walked away unaided following the fall and will now travel to Leopardstown for the Irish Champions Weekend.
"That wasn't part of the plan!" said Coolmore spokesman Kevin Buckley.
"The main thing is that I hope that Seamie is okay now as he has to get to Leopardstown now.
"Fair play to Laura Mongan. It's a great result for her. Is it the Classic that got away? Very possibly. We'll sleep on it."
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