Tottenham head coach Mauricio Pochettino was baffled by a lacklustre second-half performance that saw his team fall to a shock 2-1 Premier League loss at home to Newcastle United on Sunday.
Ayoze Perez fired home a stoppage-time winner after fellow substitute Aleksandar Mitrovic hauled Steve McClaren's visitors level in the 74th minute at White Hart Lane.
Eric Dier put Tottenham ahead six minutes from the end of a first half that delighted Pochettino but his players went on to lose for the first time since the opening day of the season in the league and spurn a chance to move into the top four.
"No-one would expect this end to the game if you see the first half," he told a news conference.
"In the second half we started to make some easy mistakes and we did not kill the game.
"At 1-0 up you always give the opponent the facility to come back into the game.
"Maybe if we analyse the 90 minutes we deserved more and the result is not fair, but then the chances that we conceded were easy for Newcastle.
"We need to assess and analyse the second half because it is impossible to see the team playing in such a different way. The first half was fantastic.
"After the first half, the team and the fans were all happy. It was clear that we could play with energy, create chances and have control of the game.
"I want to see the game again because in the second half the feeling was not the same. It was a bad night for us."
Pochettino has previously criticised the impact of Tottenham's Europa League commitments on their fixture schedule this season but he refused to blame tiredness after Thursday's 4-1 win against Monaco as a factor in Newcastle's comeback.
"It wasn't about the energy," he added. "I think there is an easy explanation – we lost control and we started to make easy mistakes.
"When we needed to play one-touch we were playing three-touch, when we should have been playing forward we dropped.
"These are easy mistakes that gave the opponents belief in the game."
"In the first half it was one of the better games we have played this season and for that we are disappointed."
