Ralph Beckett had a straightforward answer when asked before Sunday’s Prix de l’Arc de Triomphe why he had advised the owners of Bluestocking to put up a €120,000 (£100,000) supplementary fee to get her into the race. “I couldn’t find a reason not to,” Beckett said, and the gamble paid off many times in Europe’s most valuable race as the four-year-old filly came home a length-and-a-quarter in front of Aventure, under a ride from Rossa Ryan that was Plan A for Longchamp from the first stride to the last.

Longchamp is an unusual track, as much an extended loop as a circuit, and the key to riding it – which is easier said than done – is to save ground wherever possible around the sweeping turns. Ryan was fortunate to be leaving stall three, close to the rail, but all that followed was the result of his ruthlessness in exploiting his draw to the full.

This looked like an exceptionally open renewal of the Arc beforehand, with most of the field separated by about 6lb on ratings, but only a handful of the 16 runners got seriously involved.

Ryan Moore took charge on the lead from an early stage, setting a solid pace on Los Angeles, the Irish Derby winner, with Ryan and Bluestocking close behind, and once the winner had been sent for home about a quarter of a mile out, only Aventure, the runner-up behind Bluestocking in last month’s Prix Vermeille, was able to mount a serious challenge.

The one-two from the Vermeille was repeated at the line, with Los Angeles underlining the excellence of Moore’s pace judgment by staying on for third. André Fabre’s Sosie, who was sent off favourite on the local Tote at around 3-1, was fourth.

Bluestocking’s success in Sunday’s 103rd running of the Arc was a record seventh win for the famous pink, green and white colours of the Juddmonte bloodstock operation, 39 years after Rainbow Quest and Pat Eddery gave Juddmonte’s founder, the late Prince Khalid Abdullah, his first victory. It was also a first Arc win for both Beckett, second last year with Westover, and Ryan.

“I was expecting something to come and run her down late; it’s a long straight and that’s always a concern,” Beckett said. “But it was going to take a good one to go by her – she doesn’t give in easily. In the Vermeille, she got headed by Aventure and came back and beat her.

“I grew up watching Rainbow Quest and Dancing Brave and so on, so to train a winner in these colours is a huge, huge thrill. It’s a privilege to train for Juddmonte. To train an Arc winner for them as well is extraordinary.”

A six-figure supplementary fee was required to get Bluestocking into the race because the entries closed a couple of days before her successful seasonal debut in the Middleton Stakes at York in May.

“She’d been placed in multiple Group Ones at three but she hadn’t won a stakes race,” Barry Mahon, Juddmonte’s racing manager, said. “I suppose at the time we took our eye off the ball, and we said we’d go through the year and if she earns a right to be supplemented, great.”

It was Bluestocking’s Vermeille success that finally tipped the balance, and while Ryan deflected much of the credit for the victory towards Beckett and Juddmonte, his ride in last month’s success made the difference just as it did on Sunday.

“When I dissected the form, I was fairly confident, but I wasn’t confident enough to tell anyone,” Ryan said. “She fulfilled what I thought she could possibly do. I’m just the lucky one to be on her, but there’s a lot of people here who’ve done more than I have.

“The draw was key, and she’s been jumping and settling well. Once I got in behind Ryan, I got into a great rhythm and from there on had every chance to win. But we had to see what was really there and she didn’t let us down.”

It seems likely that Bluestocking will head into retirement, but the partnership between her trainer and jockey seems certain to flourish.

“He’s a better rider as each month goes by,” Beckett said. “I think the first winner he rode for me was a horrible maiden filly around Wolverhampton on a Saturday night and he wrestled her around. He had a few more of those and the relationship’s grown from there. It went to plan today, but it was his plan in the Vermeille and it was his plan again today.”