Order Of St George could be in line for a second tilt at the Prix de l'Arc de Triomphe after regaining his crown with a brilliant display in the Irish St Leger at the Curragh.

The Aidan O'Brien-trained horse is part-owned by Australian Lloyd Williams, owner of last year's Cup winner Almandin.

Order Of St George was an 11-length winner of the 2015 Irish St Leger (2800m) but suffered a shock defeat at the hands of Wicklow Brave 12 months ago.

He did bounce back to finish third behind stablemate Found in the Arc, however, and either a return to Chantilly or a bid for Melbourne Cup glory appear his two main options following his latest Curragh romp.

"He's an unbelievable horse," O'Brien said.

"He has class. You saw what he did in the Arc last year. He handles all grounds and he can stay as far as two-and-a-half miles (4000m).

"He has the choice of returning for the Arc this year or going to the Melbourne Cup. We'll think about that and the lads will decide.

"I suppose the Arc might be the favoured option, but we'll see. He'd be very comfortable over a mile-and-a-half if there is an ease in the ground at Chantilly."

Order Of St George came within a short-head of claiming back-to-back Gold Cups at Royal Ascot in June, going down after a thrilling tussle with Big Orange.

There were few challengers on Sunday (Monday AEST) as he strode to a nine-length win over Torcedor.