El Salvador gave jockey Donnacha O’Brien the biggest success of his fledgling career in the Irish Cesarewitch by seeing off Hidden Universe in the two mile premier handicap.

The 25/1 shot was due to carry top-weight of 9-12 in this marathon staying trip, but O’Brien took off a welcome 7lbs. A runner-up finish in the two mile five Queen Alexandra Stakes at Royal Ascot showed the five-year-old’s aptitude for extreme distances on the flat.

O’Brien and El Salvador started to motor into contention with two furlongs to race. The pair cut a swathe through the field down the centre of the track and this sustained challenge saw them move into pole position for the 60,000 euro prize for the winner.

Hidden Universe (8/1) and Pat Smullen though were determined to make a race of it as they stayed on into second and looked to pose El Salvador plenty of questions. However, O’Brien showed El Salvador the whip and he responded by seeing off his rival by a length.

Trainer Aidan O’Brien said: “I’m delighted and it’s great for Donnacha. It’s a hard race to win. He’s a tall fella and is doing his leaving certificate this year. It was a nice patient ride as the start was a bit messy and he was a long way back.

“He was second in the Queen Alexandra Stakes at Royal Ascot this year, and is a tough horse.”

Another O’Brien-trained horse, Marchese Marconi took third at 10/1 while Ashbury Boss (12/1) came in fourth.

Donnacha O’Brien (16) was booting home his fourth winner. This was Aidan O'Brien's second Irish Cesarewitch (Bright Horizon winning in 2010).

This gave Aidan O’Brien a Curragh treble after the earlier successes of Royal Navy Ship and Together Forever

Additional reporting by Alan Magee