“To win this kind of race twice proves that Daryz is an exceptional horse,” Barzalona told Sky Sports.
“It was a really tough race, it didn’t go as we expected but he showed his talent and that made the difference in the end.”
It was considered a gamble to keep last year’s Arc winner in training aged four, when most top-class colts are retired at three because of the lucrative breeding fees.
But it has paid off for owners Aga Khan Studs, who claimed the winner’s cheque of more than £2.5m.
Daryz added two further Group One victories to his tally this season and won his Arc prep race in grand style last month.
“He’s a good horse, he’s a champion,” said jubilant winning trainer Graffard, following his second success in the race.
“It’s rare that I am confident in the race – I always try to keep my feet on the ground because it is so hard to win these races.
“But I knew that if things were going right for him during the trip he was very hard to beat because he is a real champion.”