Descended five generations from a Niarchos family founded on mares whose names translate as "moment of madness" and “a touch of genius,” Senga repaid the bold decision of trainer Pascal Bary in securing a Prix de Diane Longines streaked with drama from beginning to end.
Only 14 of the 16 starters made it to the finishing line, after Ryan Moore pulled up Rhododendron just after halfway, while Christophe Soumillon crashed to the ground after Onthemoonagain came off worse in scrimmaging in the straight.
Rhododendron was reported to have bled and was given a positive appraisal by vets, while Soumillon fulfilled his commitments for the rest of the meeting.
Hopes of a British-trained winner looked high two furlongs out as Frankie Dettori surged to the front on Shutter Speed, but Stephane Pasquier had the move covered on Senga and Dettori was run down for the minor places close home by Sistercharlie and Terrakova.
Senga was a bitterly disappointing favourite in the French Guineas at Deauville in May and could manage only third in the Prix Sandringham – again over a mile – here on Prix du Jockey Club day a fortnight ago.
"I never gave up on her," said the vastly experienced Bary, who won this race 12 years ago with another Niarchos family blueblood Divine Proportions.
"She's got a fantastic pedigree and a great physique. Perhaps we became too fixed on the idea she was from a family of milers so we kept her on that road. But the way she was finishing off her races she was asking for a bit further."
It is one thing to step up in trip for a Classic assignment, but quite another to do it so soon after her last run.
"She ran poorly in the Poule d’Essai des Pouliches on bad ground but I don’t think that was the only excuse," continued Bary.
"She was just very flat that day. She was in much better form going to the Sandringham and the day after that run she was magnificent. So I asked Maria and Electra [Niarchos] and Alan [Cooper, racing manager] if we could run in the Prix de Diane.
"Everyone was in agreement as long as the filly was well, and Stephane was very much of the opinion we should try stepping her up. It was a risk but when the horses are in really good form you should never have a doubt about running them."
Electra Niarchos added: "It's special just to have a runner in this race. To win it, I'm just on a cloud. To see her come back and finish like this is incredible and very moving."
Senga has run four times in eight weeks and will now have a well-earned rest before decisions are made about future targets, though one race that could figure in calculations is the Prix Jacques le Marois at Deauville in mid-August, a race which the Niarchos family's Haras du Fresnay-le-Buffard have long sponsored and which they won with a previous Diane heroine, East Of The Moon.
Shutter Speed lost her unbeaten record but little else in fourth, having been given a cool ride from her wide draw by Dettori.
"She ran a very good race and I’m not making any excuses at all," said trainer John Gosden.
"She handled the wide draw as well as she could and I thought Frankie rode a very nice race. She came there with every chance but I thought the winner always held her. A mile and a quarter is the top of her range and this is one mile two and a half. We could have done without the extra half!"
Alex Pantall was proud and frustrated in equal measure after Sistercharlie flew home to snatch second, a length behind the winner.
"I’m left with a little regret because she didn’t have the best of passages, especially in the straight, having already been shuffled back when the other filly pulled up," said Pantall.
"Pierre-Charles [Boudot] had to wait a long time for daylight but she finished in magnificent fashion."
Onwards and upwards
In third, Terrakova equalled the performance of her fabled mother Goldikova in this race, staying on in determined fashion after showing signs of greenness.
"She didn’t get away too well and took a little while to get going," said Freddy Head. "She had a good trip but when the race started in earnest she was a bit caught for toe before running on well.
"She was just beaten for second and it's only the third run of her life. I think she'll definitely stay a bit further."
Dual Classic runner-up Rhododendron will hopefully get another chance to win another Group 1, and trainer Aidan O'Brien reported: "She burst a blood vessel. We think the very hot weather might have been a factor. Otherwise she's fine."