The result was sealed by a sensational 25-yard strike from Jordon Mutch in the dying minutes as the Welsh side, who were boosted by eight close-season arrivals, climbed to 11th - just three points shy of third-placed Chelsea.
With a remarkable 3-2 triumph over Manchester City already under their belts, Mackay is confident that his men are showing that they are more than equal to the challenge of Premier League football.
"Playing against really good teams, we've had lots of the ball and lots of chances," he said.
"You've got to be clinical, because it can punish you in this division.
"Chances can be few and far between so when you get them you hope you can finish them.
"I've got great faith in them, it's a great group of players and we've done very good business in the transfer window.
"The new players have settled in very quickly, there's real experience and know-how there."
Cardiff’s next challenge will see them come up against Newcastle United on Saturday.
