WATFORD, England -- Mauricio Pochettino said Tottenham Hotspur have been given "a wake-up call" by Watford in a 2-1 defeat at Vicarage Road on Sunday and that true title contenders would have won easily.
Tottenham led 1-0 after Abdoulaye Doucoure's 53rd-minute own goal but conceded twice from set pieces, with Troy Deeney and Craig Cathcart heading in and ending their perfect start to the season.
"It is so painful to concede two goals like this," Pochettino said. "It is so painful because the first half looked like a friendly game. I am very disappointed, very disappointed. If you want to be a contender -- I am the first person guilty of everything -- it is so difficult to understand, because I thought we controlled the game in the first 45 minutes.
"We scored, but when you score, you keep going and play in the same way, and then we started to change and play long ball. We conceded two goals that if you want to be a contender, you cannot concede. It is the beginning and it is a very good wake-up call for everyone, and to listen more because people talk about the perception and not the reality."
By defeating Manchester United 3-0 at Old Trafford on Monday, Tottenham joined Liverpool, Chelsea and Watford in winning their first three games, marking the first time four teams did that in the Premier League.
"The reality is if you want to be a contender, then today we should win and win easy because everything was ready to win the game," Pochettino said. "That is very painful, but I am not upset. I was more upset after Monday."
Pochettino warned his players before their trip to Watford that they would "crash" if they got carried away with their victory at Old Trafford.
"We need to show more respect to this competition," Pochettino said. "We need to compete much, much better. You need to show respect because to compete to win it is not easy. The Premier League is so, so tough.
"After the third game, because we beat Manchester United and the circumstances that we beat them in, we need to be more cautious. I think that is good today to feel the pain. It will help us for the future to be better."
Pochettino felt particularly let down because he said he told the players to be aggressive from the start and did not believe they followed that advice.
"It is disappointing because in the second half we scored, but then be more aggressive, be more strong in the situation [where Watford scored], because in every single game, you are going to find this sort of situation," he said. "Manchester City last season, Chelsea the season before -- they all concede chances like this, but if you are going to win, you need to defend well.
"It's about energy and communication. It's about being strong and showing that character and mentality to say, 'It's impossible that the opponent is going to score.'"
With Son Heung-min returning from representing South Korea at the Asian Games and Erik Lamela missing with a hamstring injury, Pochettino only had one attacking player on his bench in Fernando Llorente.
"I accept that because it's the reality," Pochettino said. "But the last three wins, when we won games, nobody asked me [about that].
"I think we have a strong squad. We showed that against Newcastle and Fulham and at Old Trafford. Today, it's not that we didn't win because of the players on the bench or the squad. The reality is we need to analyse who is on the pitch. Of course, myself first, I am responsible -- the guilty one when the team loses."