The three-year-old seemed suited by the step up in trip last time out when winning a Listed race at Leopardstown, but this contest marked a rather steep rise in grade.
Last of the field turning into the straight, the rangy filly really hit her stride in the final furlong.
Snow had set the pace but was back-peddling when the favourite Believe In Love took over, although she had no answer to Pista (6-1), who flew home under William Buick to win by a length and a half from Vivionn.
Victorious trainer Joseph O’Brien was landing a rare Group race that his father, Aidan, has still to cross off his list, while Pista was giving her sire American Pharoah a notable winner in England.
“I thought William gave her a great ride. I was a little worried because he was a little bit further back than we’d planned for most of the way and she ran around a bit in the straight, but she’s got a big engine,” O’Brien told ITV Racing.
“She’s a tall filly, so hopefully she’ll progress next season.
“There’s a nice fillies’ race on Arc weekend (Prix de Royallieu) that might suit her now if she comes out of this well.”
She was given an 8-1 quote for the French race by Paddy Power.
Buick added: “Joseph liked her and thought she came here with a good chance.
“It probably wasn’t a strong Park Hill. She had a lovely profile coming in and I thought she did it well – she’s a good, staying filly.
“I thought the race was there for an improver to come through and she was that one horse.
“I think you would have to give her that chance (in the Prix de Royallieu). She’s done nothing but progress all her life and I don’t see any reason why she can’t progress further.”
Earlier, Indigo Girl defied a slow start and signs of greenness to triumph in the bet365 May Hill Stakes.
John Gosden’s filly had won her only previous start at Yarmouth and was sent off a 100-30 chance in what looked a strong Group Two.
The Clarehaven handler was winning the race for a fifth time, having last prevailed with Rainbow View in 2008 in the same George Strawbridge silks.
A sister to the Group One winner Journey, Indigo Girl broke awkwardly from the stalls which meant she was at the back of the field early.
However, she made eyecatching progress up the stands side with three furlongs to run and was soon challenging Dubai Fountain for the lead.
Her lack of experience told as she then jinked to her left, while favourite Zabeel Queen on the far side was also running off a straight line.
However, once Frankie Dettori was able to get her straightened up to a certain degree, the daughter of Dubawi went on to win by three-quarters of a length from Dubai Fountain, with Zabeel Queen a length away in third.
It was a quick double for Gosden and Dettori after Logician’s stroll earlier on the card and the winner was introduced into the 1000 Guineas betting at 14-1 by Paddy Power.
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