Grosvenor Square led home a 1,2 for Aidan O'Brien in the Group 3 Eyrefield Stakes, with the winning son of Galileo justifying 10/11 favouritism.

Successful on debut at Galway last month, the 103-rated victor since finished third in the Beresford Stakes at the Curragh.

A half-brother to 2020 Irish Derby winner Santiago, the market leader made all under Seamie Heffernan and skipped four-lengths clear on the turn into the straight.

Ridden a furlong and a half from home, he found plenty for pressure and came home four-and-a-quarter lengths clear of stable companion Cambridge (13/2).

The well-backed Zaphod (7/2 from 11s in early shows) was a never nearer third, another three-quarters of a length behind.

"He's a lovely horse and won very well with Killian (Hennessy) first time out in Galway and then ran a good race in the Beresford," Chris Armstrong, stable representative, commented.

"He's a horse with a very good attitude, handles an ease in the ground but will go on better ground.

"He'll come back here next year and start off in one of the trials and is a typical Derby type. He's one to look forward to over the winter when he comes on physically and mentally.

"The second horse is still a work in progress. He went to Salisbury which brought him on and he was still a bit ring rusty here.

"They are two nice horses but you would love the winner."

Additional reporting by Alan Magee