Tottenham's Champions League campaign opened in desperately disappointing fashion as they slumped to defeat against AS Monaco at Wembley.

Mauricio Pochettino's side - playing in Europe's elite tournament for the first time since 2010-11 - are staging group games at Wembley as the capacity of their own White Hart Lane ground has been reduced as they build their new stadium.

And despite the atmosphere and expectation created by a record-breaking crowd of 85,011 - the highest ever home attendance for an English club - Spurs failed to rise to the occasion and paid the price for first-half sloppiness in defence.

Spurs dominated the opening phase, with Son Heung-min's shot being cleared off the line by Andrea Raggi, but Bernardo Silva's fine angled finish and a near-post shot from substitute Thomas Lemar put Monaco in control.

Toby Alderweireld's header right on half-time appeared to set Spurs up for a second-half recovery, but the expected siege never materialised, with Harry Kane missing their best chance late on.

Spurs can still escape a group that also contains Bayer Leverkusen and CSKA Moscow but this poor performance and result means they have instantly made life difficult for themselves.

Spurs did their best to make the national stadium feel like home.

The club's livery was in evidence all around Wembley and a giant flag emblazoned with the club's famous cockerel emblem was draped from the stands.

Spurs fans packed into Wembley, the attendance of 85,011 a new "home" record attendance for the Londoners, the highest English club "home" attendance and highest "home" Champions League attendance.

And despite talk of a Wembley curse, with Spurs winning on only one of their past five appearances there before this meeting with Monaco, none of the ills on show on Wednesday night can be blamed on the atmosphere.

There was a wall of sound at kick-off and Wembley rocked after Alderweireld's goal, which proved a real mood-swinger right on half-time.

Spurs will be back here for their remaining group games against Bayer Leverkusen and CSKA Moscow - and they should have no fears about the atmosphere because any problems they created for themselves. It was not a matter of an unfamiliar location or lack of support.

It was less than a year ago that Spurs were comfortably beating Monaco 4-1 at White Hart Lane in the Europa League - so the pre-match confidence was understandable and justified.

Spurs were vastly superior in the early stages but the strike from Bernardo Silva put them on their heels before dreadful marking at a throw-in and poor defending from the resulting cross ended with Lemar adding the second.

Group E is one they can still navigate their way out of - but this defeat has been an early lesson in the dangers of a lack of concentration and failure to take chances.

And it is one Spurs must learn quickly.

Kane may have got off the mark for this season at Stoke City on Saturday but the England striker is still struggling for his best form.

He was on the margins for most of this game and Spurs will hope he is back on song soon as he will be a pivotal figure in this Champions League campaign.

He is lacking the sort of confidence regular goals bring, as shown when he snatched at an opportunity he would normally put away when presented with Spurs' best chance of an equaliser late on.

The return of Mousa Dembele, on as a second-half substitute, should help Kane and he will surely be back to his best soon - something that cannot come soon enough for Spurs.