Sunderland followed up a first win in 18 league matches at Preston at the weekend with a first victory at the Stadium of Light since beating Liverpool last December.
The second successive victory in 48 hours, the first back to back wins for 20 months, moved the Black Cats into sixth position and leave a disappointing Watford still searching for their first point of the campaign.
A 39th minute penalty converted by Marcus Stewart sent Sunderland on their way and when Stephen Wright weighed in with a first ever league goal midway through the second half, there was no way back for the visitors.
Watford in fact could only muster one attempt on goal throughout the entire 90 minutes, Danny Webber forcing Mart Poom into a diving save in the 59th minute, not that Watford goalkeeper Alec Chamberlain was over-worked on the return to his former club.
But Sunderland, gaining in confidence after avoiding setting a new record of successive defeats, called the tune throughout to suggest they have turned the corner after sacking Peter Reid and Howard Wilkinson.
Manager Mick McCarthy has been forced to sell the club's best players to help reduce a £35million deficit and after tasting 11 straight defeats, expressed his delight with the double success.
"It's been a great weekend," he said. "Very enjoyable and very rare. I said we played well in the two games we lost but it's convincing everybody. I said at Preston I will take the flak if we pass it and play well and we certainly played very well today.
"The players get anxious to play well in front of the home crowd and I am pleased for the supporters they have seen us play well and win." Watford boss Ray Lewington offered no excuses but expressed his concern over the lack of goals. His side has failed to score in the league and he has no financial resources to buck the trend.
"It was a disappointing result and a disappointing performance," he said. "We were very poor and got what we deserved. We were really poor in the first half and while we showed more spirit in the second half, it was too little too late.
"We can't score goals and that is worrying. In the previous two matches we had shots saved and kicked off the line, but today it was clear to see how lightweight we are." Marcus Gayle upended Paul Thirlwell and referee Andy Hall awarded a penalty though the decision was marginal. Marcus Stewart made no mistake to give Sunderland a deserved half-time lead.
Wright, whose only other previous goal was for Liverpool in a European competition, surged clear after the impressive John Oster linked up with Stewart to slam home a deserved 67th minute clinching goal.