The summer signing scored the only goal of the game at The Molineux on Tuesday night to give Wolves their first win under McCarthy's leadership.
"It was a battling display. But to just describe it as a battling performance does us a disservice as I thought that we played really well until we gave away the penalty just before half time," the Wolves boss said.
"After Carl was sent off it we had to battle and I was pleased with how we coped.
"Matt Murray played very well in goal but he was also well protected.
"It was a great finish and a great performance all round by Jay.
"He has a lot of confidence and you need players like that to be able to handle playing here.
"Before Carl (Cort) was sent off he and Jay looked like they were forming a really good partnership."