The Lambourn handler lifted the mile Listed prize for the first time after the son of Roderic O'Connor bounced back to winning ways with a two-and-three-quarter-length victory over Lisheen Prince to initiate a double for owner Alan Spence.
Cox said: "He was impressive. He was just a bit too free in the Solario at Sandown last time out, so we gave him a bit of time off.
"He looked like he needed a bit of time off as he was going through a bit of a growing stage and he needed time to regroup.
"I am thrilled to have another nice horse for Alan Spence as we have enjoyed a lot of luck together with Profitable and Priceless.
"There is not a lot left around for him, but whether we take him abroad, we will see how he comes out of this. He is the sort of horse I expect to do well over the winter as I know the family really well.
"I've not had many winners at Pontefract as it is a long way to go, but I had my first ever winner there back in 1991 with a filly called Ushba."
Mark Johnston celebrated his 4,000th British Flat winner as Dominating struck gold in the totepool Live Info Download The App Phil Bull Trophy Conditions Stakes.
The three-year-old made it win number five for the campaign when taking the two-and-a-quarter-mile contest by three-quarters of a length to complete Spence's brace and hand winning jockey PJ McDonald his first ever century of winners.
Charlie Johnston, son and assistant trainer, said: "It is unbelievable. To start off with three horses and to have never worked for another trainer to reach this self-made is an unparalleled achievement.
"It was great to do it in these colours as Alan has supported us for over 15 years. It was PJ's 100th winner of the year which was an added bonus for him and hopefully it will be a platform to build on."
Of the 6/4 winner winner, he added: "He is a really nice horse and the long-term plan is the Chester Cup next year. Alan quite likes the idea of that as his main target."
A switch of codes could be on the cards for the Sally Haynes-trained Darksideoftarnside (13/2) after he made it second time lucky when getting up by a head in the totetrifecta Maiden Stakes.
Ben Curtis, winning jockey, said to Racing UK: "He has loads of scope to go jumping and he handles that ground - he will probably handle it softer by the feel of him. All doors are open for him."
