Billesdon Brook showed she had the capacity for the unexpected when rescuing a seemingly hopeless cause to snatch a last-gasp win in a Glorious Goodwood nursery last year.

Yet, even by those standards, she excelled herself on Sunday, when becoming the biggest-priced winner in 1,000 Guineas history after claiming a 66-1 upset victory for the jubilant Pall Mall Partners and a gobsmacked trainer and jockey, Richard Hannon and Sean Levey.

The winner's enclosure, traditionally the realm of the triumvirate of messrs Magnier, Smith and Tabor, overflowed with a 20-strong winning syndicate taken aback by what had unfolded on the Rowley Mile.

The Coolmore partners were relegated to the third spot after their 11-4 favourite Happily had struggled to live with the decisive kick shown by the winner, who collared the front-running Laurens with two furlongs to go and kept on to score by a length and three-quarters.

It was another Classic triumph for the late Bob McCreery, who bred the 1972 2,000 Guineas winner High Top and established Pall Mall Racing to campaign products of his Stowell Hill Stud before he died in 2016.

Billesdon Brook was one of two runners representing the stud along with European Free Handicap winner Anna Nerium, who ran in the colours of McCreery's wife Jeanette and was considered the number one hope. She finished seventh.

"Until Anna Nerium ran so well at the Craven meeting I thought Billesdon Brook was the winner, but then I was told it was the other one," she said.

"I was watching Anna Nerium so I didn't see what Billesdon Brook was doing. I'll have to watch the race again. This is really nothing to do with me, it's all my husband."

LONGEST-PRICED BRITISH CLASSIC WINNERS

200-1

Theodore 1822 St Leger

100-1

Otterington 1812 St Leger

Jeddah 1898 Derby

Signorinetta 1908 Derby

Aboyeur 1913 Derby

1,000-15

Caller Ou 1861 St Leger

Hermit 1867 Derby

66-1

Rockavon 1961 2,000 Guineas

Psidium 1961 Derby

Billesdon Brook 2018 1,000 Guineas

Hannon should have known Billesdon Brook had the right ingredients for a Classic victory as she had followed a familiar path in finishing fourth first time out in the Nell Gwyn Stakes.

"It was a surprise but there was nothing fluky about it," he said. "All our Guineas winners, certainly in the last ten years, have needed their first run.

"We got Sky Lantern beaten in her trial and Night Of Thunder beaten in his trial and they both went on to win their Guineas, and she was no different.

"Today she looked great. She's done no work between the Nell Gwyn and here but is obviously a very good filly.

Billesdon Brook: with connections in the winner's enclosure

"It's so nice for this big syndicate of people that have been in the game a long time and who have worked hard for a day like this."

The previous record-holder for the biggest-priced winner of the 1,000 Guineas was Ferry at 50-1 in 1918. Jacqueline Quest was also 66-1 when finishing first in 2010, but she was disqualified and placed second.

Levey, born in Swaziland and raised in Ireland, worked for Aidan O'Brien at Ballydoyle before moving to Britain where he joined Hannon. The 30-year-old has ridden plenty of winners but none previously above Group 3 level.

"It's great to put Sean on the map," said Hannon. "He's there every day and works very hard. You're defined not by how many winners you ride or train, you're defined by the good ones, the Classic winners.

Sean Lervey holds up the trophy after winning with Billesdon BrookThe Qipco 1000 Guineas Stakes (Group 1) (British Champions Series)Newmarket 6/5/2018Â©cranhamphoto.com

"She's won it well. I can't remember if I put her in the Coronation Stakes as I didn't really see this coming. We were thinking of the French Guineas. I think she's a miler. She did that very well and travelled good.

"I didn't think she was going to win. It was my father-in-law's 70th birthday and last time he was 65 when Sky Lantern won. That was a good night."

Hannon was no doubt off for another good night – and for the record, no, he had not entered her for the Coronation Stakes. It will cost £45,000 to do so.

The first prize here was £310,487.25. A Royal Ascot supplementary fee should not be a problem.

Result, replay and analysis

Members can read the latest exclusive interviews, news analysis and comment available from 6pm daily on racingpost.com