"We conceded cheaply in our box and weren't able to score goals and if you don't control the boxes it is hard to win games", said Watford manager Javi Gracia, whose side remain 13th, six points clear of the relegation zone.
"Maybe it wasn't a great performance but the most important thing was to be competitive and win the three points". "Three games to go I think we are in a good position".
Tottenham took the lead after 16 minutes when Watford keeper Orestis Karnezis spilled a cross from Kieran Trippier and Christian Eriksen scooped the ball to Alli who had the simple task of stroking the ball home from near the penalty spot.
Jan Vertonghen struck the post with a header and Kane had a goal disallowed for offside as Tottenham threatened a third goal.
The visitors are still not guaranteed Premier League safety and this defeat extended their winless run to seven matches.
The Spurs captain made his first big impact in the 26th minute when Etienne Capoue put Andre Gray through on goal, but his low effort was impressively saved by the Frenchman. 'Last year I got 29 goals so I'd like to beat that but we'll see what happens.
Pochettino has not wavered off-message, that Spurs need more time, and says their approach will not change.
Mauricio Pochettino dodged the chance to categorically confirm that he will still be in charge at Tottenham next season. They played as if the win was secured and that Watford was just showing up to the field because they had to.
The former winger told talkSPORT on a man chasing down a hat-trick of Premier League Golden Boot awards: "The main problem with Harry Kane is, when he is not on the goal sheet, his impact on the game with his team is not as relevant as what it was before".
"Of course he will be fit for the World Cup". He needs to improve still, but I'm happy.
"In the end, I'm very pleased for Hugo with some actions that showed his real quality and why he's one of the best goalkeepers in the world".
Kane scored three minutes after the break, following Dele Alli's first-half opener, to give onlooking England boss Gareth Southgate plenty to smile about and also strengthen his side's top-four aspirations.
Kane, meanwhile, was left "very sad", according to Pochettino, after being mocked by the FA Cup Twitter account following a subdued performance against United, having faced weeks of jibes from fans and players for claiming Spurs' second goal in the win at Stoke.