The current run includes the 4 - 1 humbling of Cardiff at Vicarage Rd less than a month ago.
Malky Mackay knows his side will face a tough trip to South Wales but will be bhoyed from the win over the Bluebirds at Christmas.
"It gives you belief and confidence because you know you have beaten them recently and you know the players you're coming up against," he told the Watford Observer.
"But as far as the actual game is concerned you're playing against a team that are sitting at the top of the league with a very good experienced manager and a good experienced group of players who are up there on merit.
"I believe they are one of the teams that will be there or thereabouts for going up automatically at the end of the season so we know the difficulty we face going to Cardiff.
"It's never an easy place to go and they have a lovely stadium there and an experienced team. We're going over there and it's a tough day for us but we have a real good band of fans coming with us which helps."
The visitors will be without Don Cowie and skipper John Eustace but they will include in form striker Danny Graham and two new loan signings. Andreas Weimann, a striker, has joined from Aston Villa and Andros Townsend, a winger, has joined from Spurs.