Late heartbreak for Spurs as they slump to a third straight defeat for the first time under Mauricio Pochettino
Tottenham have lost three successive games under Mauricio Pochettino for the first time after a late capitulation saw Inter Milan win their Champions League opener 2-1 at San Siro.
Spurs had looked like coming through a tough encounter with a win after Christian Eriksen's 53rd-minute opener but two goals in the final eight minutes of action saw Inter snatch the points.
Mauro Icardi's leveller was worthy of earning the victory on its own, as he struck a sweet first-time volley into the bottom corner, before Matias Vecino headed home deep into injury time.
Pochettino warned this season would be his side's biggest test and so it is proving as this loss comes on the heels of back-to-back Premier League defeats to Watford and Liverpool.
As problems with their stadium rumble on in the background, no summer signings and Harry Kane looking a shadow of his usual self, Pochettino will be wary that his side's campaign is not derailed so early on.
The Argentinian created headlines with his bizarre analogy about a cow and a train in the build-up but what he was trying to get at was that his side had to use their experience gained by previous Champions League outings.
They seemed to ignore that advice as they continually invited pressure on themselves with their insistence on playing the ball out from the back.
Inter were wise to it and pressed and Spurs could not cope, often playing themselves into trouble with sloppy passes. They were lucky not to be punished for it but the Serie A side could not find any quality in key areas.
The hosts' best moments consisted of a deflected cross from Ivan Perisic forcing Michel Vorm into a clawing save and then a drilled effort by Marcelo Brozovic which did not test the Spurs goalkeeper.
As the first half went on, Tottenham began to find their groove and Kane got his first sight of goal.
Some nice movement off the back of his marker saw him find space, which Christian Eriksen expertly picked out, and after a fine touch by Kane, the striker looked prime to convert. However, he opted to try and round Samir Handanovic but lost control and the ball ran out of a play.
They further threatened before the whistle but had to wait until the 53rd minute to take the lead.
After muscling Perisic out of the way, Eriksen crashed in a low effort which Handanovic saved well, but Eriksen got another chance and got the luck he deserved when his follow-up effort was deflected and looped over the Slovenian goalkeeper.
Vorm got down well to stop Inter levelling when he saved a Perisic header but it should have been 2-0 just after the hour as a superb run by Serge Aurier opened it up for Erik Lamela but his first-time shot was too close to Handanovic.
Lamela had further opportunities but on each occasion was snuffed out by Handanovic, who kept his side in it.
No-one would have predicted what was coming in the final few minutes.
Icardi lit up the stadium with a stunning solo effort to level in the 86th minute as he lashed home Kwadwo Asamoah's cross from the edge of the area.
Spurs went into meltdown after that and there was no surprise when Inter won it at the death when more set-piece vulnerability allowed Vecino to head home.