Donnacha O'Brien has trained his first winner with Flower Garland successful in a maiden at Dundalk.

The 21-year-old is the son of champion trainer Aidan O'Brien and younger brother of jockey-turned trainer Joseph O'Brien.

He brought his relatively short but successful riding career to an end in November last year, having been crowned champion jockey in Ireland for the past two seasons.

"It's nice to get it out of the way. She did it well," O'Brien said.

O'Brien rode 10 Group One winners during his time in the saddle, including four Classics, Saxon Warrior and Magna Grecia in the 2000 Guineas at Newmarket, Forever Together in the Oaks at Epsom and Latrobe in the Irish Derby at the Curragh.

Appropriately, O'Brien recorded his first winner as a jockey at Dundalk, aboard Quartz for his father in September 2014 when he was 16.

He sent out his first two runners at the County Louth venue last month, with Flower Garland having to settle for fifth place on that occasion.

"I have a few nice horses and it's nice to get the first one out of the way. I've 35 in at the moment," he said.

"We have a few nice well-bred two-year-olds, the likes of Fancy Blue and a few three-year-olds that haven't run.

"Hopefully there are a few decent horses there."