Piraeus - 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."
Olympiakos started brightly and were inches away from the opener when Miguel Angel Guerrero struck the inside of the post and Guilherme's follow-up effort bounced over the bar.
But the hosts gifted Spurs the lead when Kane was needlessly taken out by Yassine Meriah.
Kane saw a rare penalty saved on international duty last week, but the England captain made no mistake from the spot for his 15th goal in 20 Champions League appearances.
Four minutes later the points seemed destined to head back to London when Lucas collected Ben Davies's pass and fired home from outside the box to double Tottenham's advantage.
However, just like when they blew a 2-0 lead away to Arsenal last month, Pochettino's men allowed Olympiakos a lifeline just before the break.
Podence played a lovely one-two with Valbuena, before giving Lloris no chance with a smart finish in the bottom corner.
"We put ourselves in a great position," added Kane. "But conceding a goal before half-time changed the momentum."
Olympiakos levelled nine minutes into the second half when veteran former French international Valbuena was clipped by Jan Vertonghen.
Valbuena dispatched the resulting penalty to give the Greeks belief that a big upset was on.
However, after the 34-year-old Valbuena was replaced for fresher legs, it was the English side that looked the likelier winners in the final half hour.
Jose Sa made a great save to deny Dele Alli his first goal since January and then also stood up to Erik Lamela's near-post blast with Kane left begging for a pass that could have left him with a tap-in.