Coppull stepped up in distance to land a second Group 2 of his career under an enterprising ride from Hector Crouch, who completed a big-race double in the Visit Malta Hungerford Stakes at Newbury.
The three-year-old Clive Cox-trained colt finished third in the July Cup last time out but a bold plan to move up to seven furlongs was landed in fine style for his jockey, who also completing a treble on the card.
Crouch delivered Coppull in eyecatching style, too, peeling away from the main group towards the far side two-and-a-half furlongs from home at the head of a three-strong breakaway, a path which proved quicker to the line.
It proved a masterstroke as the Bated Breath colt stayed on too strongly to land the £93,571 pot by one-and-a-quarter lengths at 15-2 from Prince Of India (14-1) with a further three-quarters of a length back to another of the breakaway trio, the 5-2 favourite Symbol Of Honour.
Cox, who was credited by Crouch with the decision to go far side, said victory over seven furlongs had given them options for the remainder of the season.
“He was unlucky not to be a place closer at least in the July Cup but he always gave me the impression he would stretch another furlong, even as a two-year-old where he ran so well in the Coventry,” he told ITV Racing.
“He’s got a lot of class and he reminds me an awful lot of Lethal Force who won this race back in 2012 and he went on to be champion sprinter the year after he won this.
“He’s still quick enough for six furlongs and while I’m not convinced he likes it really soft, with the dry summer we’ve had we’ve got choices now.
“If he comes back all right we could still run in the Haydock Sprint Cup and that would be with a bit of confidence after today. And we still have the Park Stakes (Group Two over seven furlongs at Doncaster) which obviously he would have a penalty in.”