Mekong River maintained his unbeaten record with victory in the Irish Stallion Farms European Breeders Fund Premier Nursery Handicap at Listowel.

The Aidan O'Brien-trained colt, a 9-4 chance and having this third start, looked like being denied a clear passage at a crucial stage as Joseph O'Brien needed a gap on the rails with a number of runners in with a chance.

But the necessary room appeared and the son of Galileo took it nicely, quickening clear of 15-8 favourite Hidden Oasis, whose supporters will have thought had come with a winning run.

The winning rider said: "He's improving with racing and is a grand horse. I was happy to get the gap on the rail and he quickened up well when he got it."

Mekong River has an entry in the Beresford Stakes at the Curragh on 29 September, as well as next year's Investec Derby, and O'Brien junior added: "He seems to be coming along and it's hard to know how good he is."

Barry Geraghty celebrated a winner on his 34th birthday as Tropical Three claimed the I.T.B.A. Fillies Scheme Hurdle for trainer Michael Hourigan.

Little King Robin tried to stretch the field on the run to the second-last but Tropical Three stuck at it and scurried away after getting on terms from the final flight.

A length and a quarter was the margin of victory for the 13-8 favourite, with Lady Of Glencoe back in third.

Hourigan said of the lightly-raced winner: "I think she is a very good mare and the dream is alive for another while.

"Barry said it was her class that won it for her and she was going away at the line.

"I've had a number of the family, including Tropical Lake, and that's why i bought her.

"She's crying out for further and for fences."