Tottenham manager Mauricio Pochettino questioned his side's attitude after letting a two-goal lead slip to draw 2-2 away to Olympiakos in their Champions League opener on Wednesday.
Despite a slow start, two goals in four first-half minutes from Harry Kane and Lucas Moura put last season's Champions League finalists on course for what would have been a vital win in Group B.
However, Olympiakos and are now unbeaten in their last 18 games in all competitions stretching back to February and showed why as Daniel Podence and Mathieu Valbuena struck either side of half-time to secure a well-deserved point.
A point away in front of a passionate crowd in Piraeus is not a disastrous start for Pochettino's men, who took just one point from their opening three group games last season before an improbable run to the final.
However, Pochettino is concerned that Spurs have won just two of their opening six games this season and face the might of Bayern Munich next in the Champions League.
"I think it's easy to explain. When we are not showing that intensity that the competition demands, we struggle," said the Argentine.
"It's not about tactics, it's not about quality players, it's about the quality of preparing yourself to be ready to fight.
"At this type of level you need to match the opponent in terms of intensity, aggression, in excitement and motivation and then is going to appear your quality when you are connected with the game."
"But conceding a goal before half-time changed the momentum."