Despite racing lazily at various stages of the three-mile Grade One, Don Poli responded to Cooper’s urgings and joined Kings Palace for the lead when that horse made a mistake in the back straight.

The two of them fought it out coming down the hill before Don Poli asserted from the home turn.

Southfield Theatre briefly appeared a major threat jumping the second-last, but Don Poli powered away from the last for a six-length success.

Wounded Warrior, like the winner owned by Gigginstown House Stud, was third.

Cooper, who suffered an awful injury at last season’s Festival, said: “To get a winner this early (in the meeting) is great. I’ve been supported by great people.

“Willie’s done a serious job with this horse. He could be very special.”

Gigginstown supremo Michael O’Leary said: “He always seemed quite comfortable, if anything Bryan had to wake him up.

“It’s another outstanding training performance by Willie Mullins – the man’s a genius.

“I have a very good jockey and a great trainer. It’s great not to have to wait until Friday for a winner.”

Asked whether he could be a Gold Cup horse next year, O’Leary added: “I’ll enjoy today, there’s no point planning for next year – that will take care of itself.”

Mullins said: “It was special. It looked like he was idling the whole way up the straight, ears pricked.

“It looked like he’d have won the four-mile chase after all!

“If that’s the best in Ireland and over in England, you’d have to say that (he could be a future Gold Cup horse).

“We’re a bit numb. The week has gone way above our expectations.”