Southampton - Marco Silva's Watford climbed to fourth in the Premier League on Saturday after a 2-0 win at Southampton to remain unbeaten in their opening four games for the first time.
Goals in either half from Abdoulaye Doucoure and substitute Daryl Janmaat maintained Watford's jaunty start to the campaign which began with their fighting 3-3 draw with Liverpool.
Southampton offered little resistance under new coach Mauricio Pellegrino with their only shot on goal coming in injury time as the Argentinian suffered his first league defeat since taking over at St Mary's.
Watford went close to grabbing the opener with the game 22 minutes old when Jose Holebas curled a 25 yard free-kick over the Saints' wall, the ball narrowly edging the wrong side of the post.
As the interval approached Southampton's defence was troubled by a long throw-in from the left from Holebas, the Greek international marking his 50th appearance for Watford. Jack Stephen's attempt to clear resulted in Doucoure foiling keeper Fraser Forster with a superb 25-yard volley.
On the stroke of half-time, Doucoure -- among the scorers for Watford against Liverpool -- was not a million miles away from getting a double only for the Mali-born French midfielder's long-range attempt to fly over the bar.
Southampton left the pitch accompanied by boos from some of their fans who were given further cause to feel disgruntled when Watford doubled their lead after the hour.
Tom Cleverley headed a partial clearance to Janmaat and minutes after coming on the Dutch defender sealed the win, firing a 30-yard shot past Forster and into the bottom corner.
Pellegrino took immediate action to try to shift the balance of power, the Argentinian replacing Manolo Gabbiadini with Shane Long, and Sofiane Boufal with Charlie Austin.
But as the home fans voted with their feet and headed for the exits Watford held out for a deserved win, their first against Southampton since 2008 with their hosts down to 10th.