Mauricio Pochettino laid into his players and admitted Tottenham are now under pressure in their Europa League group having lost to Anderlecht in Brussels.
Christian Eriksen had put Spurs ahead as the visitors started the game well, with Clinton Njie replacing Harry Kane as the focal point of their attack.
But, after a host of missed chances, Spurs were made to pay as Guillaume Gillet levelled before the break and Stefano Okaka swept home in the second half to seal a 2-1 win for the Belgian outfit.
The result leaves Group J wide open with two points separating leaders Monaco and bottom side Qarabag – with both Tottenham and Anderlecht now on four points.
Pochettino, who threw on Kane with the scores level despite revealing he had suffered a knock in Saturday’s draw at Liverpool, did not hold back in his assessment of the performance.
“We started the game very well,” he said.
“After 10 minutes we scored, we created two or three chances more and when you concede the chance to the opponent to get back into the game the way we did the dynamic changes. We lost our focus and after 10 minutes changed the game completely.
“This was our problem and we need to learn. We are young but if you are the best team on the pitch after 10 minutes and you believe you can win the game you need to win the game. We lost our focus.”
Pochettino, normally mild mannered, expressed his dissatisfaction with his players’ inability to put them in a prime position to qualify for the knock-out stages.
“I am angry, frustrated, disappointed. I don’t know which word to describe me.
“We need to be focused for 90 min, 95 min. Football is like this. We are under pressure now. We have to win but I am happy about that. We need to feel the pressure. Because if not, after 10 minutes it seemed like it was an easy game and we have lost.”
Anderlecht coach Besnik Hasi was pleased to see his side pick up their first win in this season’s competition and believes they did a great job of recovering from the early setback of Eriksen’s goal.
“It’s nice to win against such a team,” he said.
“Especially after the poor start against Monaco and Qarabag – we knew it was our last chance today. In the second half we put higher pressure on them and played with much more courage.
“After the break we dared more with a 4-3-3 formation so we got more space and opportunities. Tottenham clearly came to win and gave the necessary space away for us to exploit.”