The rider had to weave his way through the field aboard the three-year-old, who was finishing strongly, but could not reach Enable in time as the pair came within a short neck of lowering her colours.
Watch how Sea Of Class came agonisingly close to winning the Prix de l'Arc de Triomphe at ParisLongchamp
“It was absolute agony. I was heartbroken, more so for everyone that has been connected with her – her owners and William and Maureen (Haggas),” Doyle told At The Races.
“I know we bang on about how much it is a team effort, but it truly is and this filly has come a long way in a short space of time.
“She is a completely reformed character to the one we first dealt with back in the spring. From my point of view, everyone wants to win the Arc and when you get that close it was a real sickener, but she was beaten by an absolute superstar.
“Enable ran a hell of a race. To do that on her second start of the season and her first run back on turf since the Arc last year was an amazing performance. Full credit to them.”
Doyle explained the reasons behind the hold-up tactics he employed after consulting the best jockeys in the business.
“I guess it’s easy for the untrained eye to watch a race and say ‘he’s come too late’, but anyone who had seen Sea Of Class run previously knew what was going to happen,” he said.
“All the top-class jockeys I spoke to, from Maureen talking to her father Lester (Piggott), to myself talking to Kieren Fallon, they all said you can’t change a horse’s running style just because you are running in a different race with a tricky draw and the rest of it.
“We stuck to our game plan. There are many factors you would like to change, but you can’t.”
He went on: “The draw was no help to us, the size of the field was no help to us, and the amount of horses running in the race that had no chance we couldn’t change.
“I didn’t have to put on the brakes. There was just one slight moment when I had to angle out a tiny bit and the horse on my inside just shifted and it pushed me a slightly bit left.
“It was just the ground I had to give away. That was the concerning thing and I was concerned right the way through.
“There was no one more frustrated than myself at being beaten. It’s the richest race in Europe and it’s a sickener, but you can’t change it.”
William Haggas hailed Sea Of Class “a pretty special filly” the day after she came agonisingly close to providing the Newmarket trainer with a first victory in the Prix de l’Arc de Triomphe.
The Irish and Yorkshire Oaks winner almost defied the hindrance of being drawn in stall 15 and passed all bar the brilliant Enable in the straight, going down by a short neck.
Haggas confirmed the filly would not run again this season – but that it is almost certain the daughter of Sea The Stars will stays in training as a four-year-old.
“I think she’s OK, she got back at lunchtime, I’ve been at the sales all day and I’ll see her later on,” Haggas said on Monday.
“She won’t run again this season, she’s given her all and had a lot of hard racing – she’s done plenty.
“I think if we were going to retire her we may have looked at another run, but we’re not going to. I think the plan is to keep her in training, so I think we’ll call it a day.
“She’s come a long way in a short space of time, she didn’t win her Listed race until May and she nearly won an Arc in October. She’s a pretty special filly.
“Hopefully she can go one better next year.”