Kieran Trippier’s second-half strike, his first goal for the club, was enough to seal all three points for Spurs, who have recorded four consecutive league victories for the first time in two years.
Mauricio Pochettino’s side are now one point above Manchester City, who they play at the Etihad Stadium next weekend, and five behind surprise leaders Leicester with 13 games to play.
“We are second now, we keep moving on in the table so that is good,” Lamela said.
“We keep winning which is very important for us, but the next one at Manchester City is more important now.
“I hope we can beat them but we expect a difficult game. Every game is difficult, every game is important, so we need to keep training to give the maximum next week.
“For me, I feel confident and I am training hard like my team-mates. Everyone trains hard to do their best on the pitch and I think this team is a very good team because we have quality and we are all together to fight.”
Pochettino admits his players are finally starting to believe they can win the Premier League title.
“You can see in their eyes, the feeling, the energy, that they believe. In football belief is the most important word. If we believe, anything can happen. I believe in my squad and they believe too in the way we play. This synergy is very important for the future.
“But it is better not to speak too much, only to show, to work hard.
Watford drop to 10th after winning just once in eight matches and the visitors were flattered by the scoreline at White Hart Lane. The Hornets failed to register a single shot on target and goalkeeper Heurelho Gomes, who was playing against his former club, admitted it was a tough afternoon for his side.
“It was difficult. I believe that in the first-half we didn’t really play our football.”
“Tottenham made it a very difficult day for us but we knew from the beginning that we were going to play against a tough opponent, and they showed today why they are second in the table.
“We did great to hold them for a long time and at the end we tried to score our goal, but it was too late.”
Spurs created several good chances in the opening hour but continued to be thwarted until the introduction of Dele Alli off the bench instigated a breakthrough.
Three minutes after coming on as a substitute, it was Alli’s cross that laid on Trippier to score and Gomes admits the 19-year-old midfielder was the gamebreaker.
“He made the difference when he came on. He passed the ball for them to score the goal, and it was very tough for us,” said Gomes.
“It’s not easy to come here, especially when you’re having to defend for large parts of the game, but we showed character.”
Gomes spent six years at Tottenham after moving to London from PSV Eindhoven in 2008 and he played 136 times for the club.
The Brazilian remains a popular figure among the Spurs faithful and was given a warm reception on his return.
“It was very special,” Gomes said. “I’ve played here before against them but I’ve never played here since I left the club. It was a great reception and I really want to thank them for it.”
Lloris, Trippier, Alderweireld, Wimmer, Davies, Dier, Dembele, Lamela (Son 72), Eriksen (Carroll 90), Chadli (Alli 61), Kane.
Walker, Rose, Mason, Vorm.
Gomes, Nyom, Cathcart, Britos (Prodl 54), Ake, Mario Suarez (Behrami 46), Watson, Abdi (Deeney 46), Capoue, Jurado, Ighalo.
Amrabat, Pantilimon, Anya, Holebas.