Luxembourg moved to the head of the market for next year's Cazoo Derby after he ran away with the Alan Smurfit Memorial Beresford Stakes at the Curragh.
Trained by Aidan O'Brien and sporting the colours of Westerberg, who own the colt in partnership with the Coolmore team, Luxembourg was completing a big-race double for connections as Tenebrism had landed the Cheveley Park Stakes at Newmarket just moments before.
Much like that filly, Luxembourg came from a seemingly unpromising position at the back of the field in the mile Group Two to win in style.
Tuwaiq, who Luxembourg had beaten on his only previous start at Killarney in July, was in front at the furlong pole for jockey Gary Carroll, but when Seamie Heffernan switched the winner to challenge, the response was instant.
Luxembourg quickly assumed control and stretched away, despite showing a few signs of greenness, to win by four and three-quarters lengths from Manu Et Corde.
Heffernan said: "He's very smart at home and he's proven it twice now. I was very impressed - very talented, very smooth.
"The most impressive thing about him is he knows he's good and he doesn't show it off. He doesn't show you until you press the button and say 'give us a look'.
"When you have that turn of foot a mile is well within his comfort zone.
"His dad was a good staying horse that had the pace and class to win a Guineas. If Aidan wants to run him in the Guineas he'll change his galloping procedures and if he's targeting the Derby he'll go a different route.
"The turn of foot he showed me today was pretty exciting. I'm not sure what he's going to be targeted at, but he couldn't have done that any easier."
Speaking from Newmarket, O'Brien added: "We've always thought the world of that horse."