"I saw So You Think start to go and I followed him. At the 250 (metres) I am going to catch him.
"I definitely enjoyed that moment. It's something very special."
This year, it is something of a "French fraternite" with De Royer-Dupre joined by Mikel Delzangles and his charge Dunaden who is now the defending champion's nearest challenger in the betting.
They both had their strongest workouts on Friday since their respective wins in the Moonee Valley Cup and Geelong Cup.
And the difficulty punters are having in separating the French pair was reflected in the opinion of Dunaden's trainer Mikel Delzangles.
Delzangles, who returned to Melbourne this week after a fortnight at home in France, said he was happy with his horse's progress, noting also that Americain had maintained his impressive form.
"Americain is the favourite and he should be favourite," Delzangles said.
"I am very happy when I see he is favourite.
"For sure he is very, very happy in Australia.
"But I know each time we race against him we beat him."
In the Americain camp, stable representative Stephanie Nigge maintained her routine with the horse working over 2000m as he does almost every morning.
The only difference from one day to the next is the speed at which he performs, which on Friday was three-quarter pace.
"It is the same again, he likes it," Nigge said.
"There is no need to change anything, the horse is happy and he is fit.
"I don't think about other horses, only him.
"But I know Dunaden is a very good horse and he is very well.
"We have respect for him."
Like most of the visiting trainers, Delzangles is hoping for some rain to soften the Flemington track after three days of high temperatures and strong wind in Melbourne.
Delzangles is also anxiously awaiting the outcome of Craig Williams bid to ride Dunaden on Tuesday after he lost an appeal against a 10-meeting suspension.
Williams will appear before the Victorian Civil and Administrative Tribunal on Monday to seek a stay of proceedings which will allow him to ride in Tuesday's Cup.
Just in case Delzangles has taken the precaution of sending for French rider Christophe Lemaire who has been riding in Japan.