Seamie Heffernan was the star of the show on the final day of the Flat season at Leopardstown as he rode a treble for the Aidan O'Brien team.

The highlight was the performance of Mekong River in the Eyrefield Stakes and the youngster (4-6 favourite) has been pencilled in for a Group One event at Saint-Cloud next weekend.

He led all the way in the Listed contest to maintain his unbeaten record after four races with an impressive six-and-a-half victory.

Heffernan opened his account in the Irish Stallion Farms EBF (C & G) Maiden when newcomer Blue Hussar (7-2 joint-favourite) flashed home late to win by three-quarters of a length.

He also took the other Listed race on the card, the Knockaire Stakes, when Francis Of Assisi (9-2) came with a late challenge to catch favourite Big Break and score by a length and a half.

Dermot Weld has been added to the Aga Khan's roster of trainers and he could not have had a better start for his new patron as Balansiya spreadeagled the opposition in the Irish Stallion Farms EBF Fillies Maiden.

Settled in second by Pat Smullen, the daughter of Shamardal (11-4 joint-favourite) quickened into the lead at the top of the straight and streaked clear, winning by seven lengths to earn quotes for next year's 1000 Guineas.

The Rosewell House handler landed a double when the Leigh Roche-ridden Elegant Peace (14-1) found a nice gap to lead in the www.leopardstown.com Nursery and then dug deep to hold the strong challenge of Balmont Blast by a neck.

It was fitting that the curtain should come down on the season with another big-race winner for the remarkable jockey Johnny Murtagh.

He could be spotted travelling sweetly into the straight in the Movember Handicap on the Jimmy Lambe-trained Sir Ector (14-1) and once he hit the front he had enough in the tank to hold Quick Jack by half a length.