"Coming back after a two-week international break you always hope that you have done the right thing in terms of the time you have given off, the training you have done, the fitness work you do and just the boys being away from each other for a couple of days.
"To end up with a performance like that I was very, very pleased."
Asked about the contribution of Heidar Helguson the Scot added: "I know that he's going to cause problems for the centre-half and the partnership with him and Danny Graham, certainly today caused people problems.
"I am delighted that Danny Graham got his goal because he's been working so hard every day in training and he worked so hard in games."
Scunthorpe have now conceded 12 goals in four league games and boss Nigel Adkins said: "Obviously the goals they gave away I am very disappointed with.
"We knew that Watford were a good side, very lively and industrious in the centre of the park and having Henri Lansbury with us last year, we knew that.
"I thought the three of them in their (midfield) were superb and the front two did very well, and the front five I thought they were excellent.
"We've come away from home to try and nullify that as best as possible to give ourselves an opportunity to go forward and score, and we did create chances, but if we can't defend a simple cross into the middle of the six-yard box then we're not going to win games of football, it's as simple as that."