McCarthy declared the victory as a dream come true for him and described Martinez as a "tactical genius".
The Scottish-born Republic of Ireland international, who moved south from Hamilton in 2009, told ESPN: "It's an unbelievable achievement. I'm speechless to be honest. It's a dream come true, it's what you dream of as a kid."
He added: "I think the gaffer is a tactical genius. It's down to his tactics what we've done."