Aidan O'Brien reports Leading Light to be in tip-top shape ahead of the Palmerstown House Estate Irish St Leger at the Curragh on 14 September.
Last year's Ladbrokes St Leger winner goes for his second Classic in good form having won all his three starts this season including the Gold Cup at Royal Ascot.
The four-year-old returned after a break to win the official trial for the race over the full course and distance.
"He had a break after Ascot and it was nice to get a run into him back at the Curragh," O'Brien told At The Races.
"We're very happy with him and he seems to be in good form since. Hopefully he will progress on to the Leger, his next start.
"Hopefully he will progress on to the Leger, his next start" - Aidan O'Brien on Leading Light
"Last year he went on from Doncaster to the Arc. He was drawn wide and was slowly away and got back behind a wall of horses and never got racing really. He finished a very fresh horse really.
"Obviously we will look to next year's Ascot Gold Cup again and the boys (owners) will decide after the Curragh if he will run again or finish for the year."
Among his rivals will be Dubai Gold Cup victor Certerach, who disappointed behind Pale Mimosa in the Lonsdale Cup at York last month.
"All being well he'll go for the Irish Leger," said trainer Mick Halford.
"He disappointed in York the last day but probably didn't travel as well as usual and I'm looking forward to getting him back on home turf so he won't have too far to go.
"We are shelving the Melbourne Cup this year and maybe think about it for next year. We'd love to back to Dubai with him and I didn't want to jeopardise that.
"The Irish St Leger looks to be a wonderful, tough race. There are some great stayers around at the moment with Leading Light, Pale Mimosa and Royal Diamond. It will be very competitive, but it would be nice to be part of it all.
"He's ground dependent, so I'd be inclined to let him down after the Irish Leger and bring him back for Dubai."