The sharp-witted master of Heath House has enjoyed multiple Group One victories at home and and abroad during a distinguished career dating back to 1970, but is a self-proclaimed reluctant traveller.
Speaking after seeing Alpinista notch a fifth successive top-level win in August's Yorkshire Oaks - her first on British soil after previous triumphs in Germany and France - Prescott said: "It's not superstition, I just don't go abroad if I can possibly help it!"
With her triumph on the Knavesmire marking her down as a leading Arc contender, however, Prescott was ultimately persuaded to cross the Channel for Europe's premier middle-distance contest - and it certainly proved a worthwhile trip.
"I think it's the best day of my racing life. I always thought the best day of my racing life was when I rode a winner on my first ride when I was 15 or 16," he said.
"It had got no chance of winning and it won. I had a girlfriend and we walked down the track afterwards and there was an old man banging in divots and he said 'what won the first', and I said 'I did' - I thought it was the best 10 minutes of my life!
"But I think this is every bit as good, if not better."
Following a relatively dry weekend in Paris, the heavens opened spectacularly in the minutes leading up to the great race, encouraging punters to back Alpinista down to clear favouritism.
And while the mud was flying in all directions, the race itself could hardly have gone more smoothly for the grey as she cruised in third gear for much of the mile-and-a-half contest, with Luke Morris still sat motionless in the saddle approaching the final furlong.
French Derby winner Vadeni dispelled doubts about his stamina with a strong finishing effort, while for a moment it looked like Frankie Dettori might be delivering last year's German hero Torquator Tasso with a perfectly-timed challenge in his bid for back-to-back wins.
But Alpinista did not shirk the issue when challenged and held Vadeni and Torquator Tasso at bay by half a length and a neck respectively.
"I've never won an English Classic and I'm very ashamed of it, but I'm very proud having won the Prix de Diane and even more proud having won today," Prescott added.
"I've trained for Miss Rausing (owner-breeder) for 36 years, I've trained the grandmother and the mother and Luke has been with me for 11 years. It's hard to imagine a better day if you're a racehorse trainer.
"I feel for poor William Butler, who has been my assistant for 20-odd years and I think he'll view this win with mixed emotions in that it will keep me tottering on a bit longer!
"For all of us at Heath House, I can't emphasise enough how special a day like this is. We're very lucky to get one."
For Kirsten Rausing the result was the culmination of a lifetime's work.
She said: "I'm delighted, thrilled and extremely grateful to have been able to produce this marvellous mare.
"I think she's a sixth generation homebred and none of this would have been possible without my team at home.
"My immense gratitude goes to master trainer Sir Mark Prescott and Luke Morris, who has ridden the filly to all her Group wins and it was a fantastic riding performance today."
Alpinista has very much catapulted her rider into the big time over the course of the last 18 months and he was understandably thrilled to have delivered on the biggest of stages.
Morris said: "They went a very solid, even gallop throughout. I knew Titleholder would probably roll along and I was a bit concerned at halfway that I was a bit closer than I wanted to be.
"But she's towed me into the race and I was able to sit on her until nearly the furlong pole. During the last couple of weeks I must have watched the last 25 Arcs and I've not seen one sit to the furlong pole, so she's extremely special.
"This is very much the pinnacle of my career so far and I can't emphasise enough how grateful I am to Miss Rausing and Sir Mark for giving me this opportunity.
"I had to hold back the tears coming back in. When you have these Group One winners, it just makes you crave them even more and work harder to get them in the future."
Alpinista is set to retire to the breeding shed next spring, but one last dance could be on the agenda.
Rausing said: "The future, first of all, involves getting home safe and sound to Newmarket. The further future is she'll come back to the stud next year, and in between then we need to sit down and discuss what happens.
"There is the Japan Cup and there's the Breeders' Cup, possibly."
Prescott is clearly keen on an Asian adventure, saying: "I'm sure Miss Rausing's eagle eye will have observed that she gets a £3million bonus if she's lucky enough to win the Japan Cup, on top of the prize-money!"