Jargelle foiled Richard Hannon's attempt to maintain his stranglehold on the Weatherbys Super Sprint when just holding Infamous Angel in today's Newbury feature.
The 20-1 chance, trained by William Haggas, made virtually all the running under Liam Jones in a desperate finish, beating Infamous Angel by a short head with Senor Mirasol a nose away in third.
Haggas, successful with Superstar Leo eight years ago, revealed Jargelle had not been the most straightforward.
He said: "This one was bought by Gill Richardson who doesn't get many for me but at 28,000 guineas it was great value.
"She hasn't been easy and 'Yarmy' (Steve Dyble) seems to have been with her for ever and ever. He had one to do in the 1.30 at Newmarket and sent one of his henchmen to stand in today and everything worked out perfectly.
"It's great for Liam who has really worked hard. He deserves more opportunities."
Haggas will now look at a Listed race for Jargelle, adding: "The Watership Down Sales race at Ascot is a possibility but the St Hugh's Stakes would be ideal, being over five furlongs and about a month from now.
"She can have a little break and then hopefully come back here and pick up some black type."
It was a biggest career win for Liverpudlian Jones, who said: "I rode her at Warwick and Nottingham and thought she was improving. She jumped really well, travelled well in front and then picked up. I don't think we were headed."
Richard Hannon was delighted with Infamous Angel, who just failed to give him a seventh win in the race.
However, the trainer expressed his frustration that the 3-1 favourite Penny's Gift never got into the race under Martin Dwyer.
The filly was denied racing room and had to be switched, was then bumped yet went down by around two lengths as she finished best of all.
Hughie Morrison is looking towards next month's Deauville festival with Intrepid Jack after his clear-cut success over Corrybrough in the Uplands Racing Hackwood Stakes.
Enjoying the quick ground, the 12-1 chance scored by two lengths under George Baker in the Group Three sprint.
"Granted similar ground he could go for the Maurice de Gheest, although he had a slightly crusty nose this morning and I almost didn't run him," said Morrison.
The winner is in the Coolmore Nunthorpe Stakes at York next month for which William Hill cut him to 40-1 from 66-1.
Henry Cecil produced the training feat of the day as he brought last season's Oaks favourite Passage Of Time back from the brink of retirement to land the David Wilson Homes Steventon Stakes by a neck from Bankable.
A Group One winner as a two-year-old, the 10-1 chance had finished last in the Brigadier Gerard Stakes at Sandown in May.
However, she returned to form in style as she gamely resisted the determined challenger.
Cecil is now considering stepping her back up to Group One level in the Blue Square Nassau Stakes at Glorious Goodwood in two weeks' time.
"She's in the Nassau but we'll have to see," he said.
"She's coming back and had just started to work better in the past 10 days. A lot of these four-year-old fillies take a while to come and at Sandown the ground was terrible."
Bankable's jockey Dane O'Neill got a one-day ban (August 4) for careless riding for his troubles.
Michael Stoute's game filly Lindelaan (7-2) got home by a short head from dead-heaters Fragrancy and Eva's Request in the Bathwick Tyres EBF Fillies' Stakes.
Gary Coffey, racing manager to winning owner Renata Jacobs, said: "She'd been beaten in two photos and it was nice to see one going our way."
Doctor Crane (9-1) and Robert Havlin landed the Trailfinders Conditions Stakes by a length and a head from Oratory and Awinnersgame for John Gosden, who was at Newmarket where he landed a double.
Hunting Country (9-2 favourite) looks worth following after powering to a four-length triumph over Pinch Of Salt for Mark Johnston and Greg Fairley in the Pubs Call 08703518834 For Racing UK Handicap.
Duran Fentiman picked up a two-day ban (August 3 and 4) for careless riding on third-placed Rosbay.