A Joshua King brace was sandwiched by goals from David Brooks and Callum Wilson, while Watford were reduced to 10 men when Christian Kabasele was shown a second yellow card in the first half.
"It's a great result for us and we're delighted with that," he said.
"I would say that we have played better than that, but we're certainly very pleased with that result and our position off the back of it.
"Both centre halves were dominant and Jefferson Lerma did a good defensive job in front of them, I'm really pleased with their work.
"We were very good in both boxes today, which was a flip from our last away game at Burnley [a 4-0 defeat]. It was an incisive, efficient performance and we dealt with the physical contest really well.
"Wins obviously give you the confidence and belief you need to win really difficult games in the Premier League.
"There's tough games to come, we need those mental qualities shown today to push on and get more results.
"Nothing is a given in this league, we will enjoy where we are but we have to maximise this period."
Opposite number Javi Gracia, meanwhile, was unhappy with a below-par display that made it four Premier League games without a win for the Hornets.
"It is always a bad moment to lose like today," he said.
"Today is the first day we haven't competed as in other games. They were much better than us. We will try to improve for the next game."