Piraeus, Greece - Tottenham failed to get off to a winning start in the Champions League as last season's finalists let a 2-0 lead slip to draw 2-2 with Olympiacos in Greece on Wednesday.
Despite a slow start, two goals in four minutes from Harry Kane and Lucas Moura put Spurs on course for vital win in group B.
Olympiacos fought back and are now unbeaten in their last 18 games in all competitions stretching back to February. They were well worthy of at least a point as Daniel Podence and Mathieu Valbuena struck either side of half-time.
A point away in front of a passionate crowd in Piraeus is not a disastrous start for Mauricio Pochettino's men, who took just one point from their opening three group games last season before an improbable run to the final.
There will be concern 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.
Olympiacos started brightly. Podence forced Hugo Lloris into the first save of the game inside 10 minutes.
The hosts came even closer moments later when Miguel Angel Guerrero struck the inside of the post and Guilherme's follow-up effort bounced over the bar.
Pochettino left out Son Heung-min from the starting lineup even though the South Korean scored twice in a 4-0 win over Crystal Palace on Saturday, which the Argentine recognised was by a distance his side's best performance of the season so far.
The visitors' missed Son's energy and goal threat early on, but were gifted 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.
Pochettino's men, who blew a 2-0 lead away to Arsenal last month, allowed Olympiacos 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.
Tottenham thought they had restored their two-goal lead when Dele Alli found the net early in the second-half, but the England midfielder was rightly flagged offside.
Instead, Olympiacos went down the other end and levelled. Former veteran former French international Valbuena was clipped by Jan Vertonghen and dispatched the resulting penalty to give the Greeks belief that a big upset was on.
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 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.