Black Tears got up in the final strides to give trainer Denise Foster a first Cheltenham Festival winner in the Close Brothers Mares' Hurdle.
Foster is currently in charge of Gordon Elliott’s string at Cullentra House Stables in County Meath while he is serving a suspension.
Jack Kennedy produced Black Tears (11-1) with a perfectly-timed challenge to deny the Willie Mullins-trained 10-11 favourite Concertista in a thrilling finish to the two-and-a-half-mile contest.
Great White Shark and Floressa made the early running, with Roksana and Indefatigable tracking them and Concertista held up at the rear.
The complexion of the race changed coming down the hill when Roksana made her bid – but Concertista was hot on her heels.
The latter looked the likely winner when she jumped the last in front, but she had no answer to Black Tears, who got up to win by a head with Roksana two and three-quarter lengths away in third and Indefatigable fourth.
Elliott was suspended for 12 months, with the last six months suspended, after an image of him sitting on a dead horse appeared on social media. Foster took over the licence at the yard last week.
Kennedy said: "It's unbelievable – I’m absolutely delighted for the owners.
"It’s great for 'Sneezy’ Foster as well – a massive team effort goes into getting the horses here every year, so it’s brilliant for the team.
"She jumped and travelled unbelievably well. She came out of my hands at the last – but luckily she was more tuned in than I was, and that was probably the difference between winning and losing.
He added: "It’s massive that she’s won (given the recent headlines). The amount of effort that everyone puts in at home it’s days like these that make it all worthwhile.
"We’ve gone through a bit of a tough time, but we’ve kept going and showed that today."
Lisa O'Neill, yard representative, speaking from Cullentra House Stables, said: "Denise was the first one on the phone and she was absolutely over the moon as it was her first Cheltenham winner and hopefully it won’t be her last.
"Black Tears is a very genuine and consistent mare and this result is great for her owners Aidan and Caren Walsh and John Lightfoot, as they have been brilliant supporters of Cullentra House. It is fantastic for them and the whole team here.
"I think Jack Kennedy gave her a great ride. He took the paint off the rail and rode her for a bit of luck. She was beaten just over two lengths in the Coral Cup last year so to get her head in front this is great.
"She had that course form so there was no question about that and she was always going to be staying on having run over slightly further at the meeting last year.
"She showed a great bit of stamina and dug deep and battled hard when she needed to the most. We will get her back and just enjoy today. We will speak to the owners and then decide what to do next."