His half-brother Tangerine Trees took Europe’s premier five-furlong prize in 2011 for his sole triumph at the top level.
Tangerine Trees could only finish 10th in his one attempt at the Nunthorpe, while Alpha Delphini dramatically stepped up on his eighth place in 2017 to spring a 40-1 shock on the Knavesmire last month.
Bryan Smart, who has trained both horses, admits he has not yet come down from the euphoria from that day.
“He was fantastic and I’m still walking on air,” said Smart.
“All the staff have been brilliant and the owners supported us to go there.
“It was a big shout to leave the sheepskins (cheekpieces) off at York but Graham (Lee, jockey) guided us there.
“He’ll probably go to France. Breeders’ Cup, I think no, but we’ll look at all the options.
“He’s got one up on Tangerine Trees. He’s won a Group One before he goes to France but ‘Tange’ hadn’t.”