Tommy Smith, Danny Graham and Tamas Priskin scored the goals for the Hornets and Mackay thinks his side are heading in the right direction.
He told the club's official website: "We're getting there now.
"The build-up has gone up another notch and to come out of the game having played well in the main and scored goals is another positive step towards Saturday.
"To play a level of opposition like Parma and play the way we did at times means that overall I am happy."
Source: Team_Talk