From Tottenham Hotspur Stadium - Tottenham were held to a 1-1 draw by Sporting CP on Wednesday evening, missing the chance to secure qualification to the knockout stages of the Champions League.
A win would have sent Spurs through to the last 16, while Eintracht Frankfurt's win against Marseille meant a victory would have allowed them to top the group, but qualification now rolls over to matchday six with Antonio Conte's men one point clear in first.
Tottenham very nearly found a clear sight of goal early on when Eric Dier's searching ball over the top reached Lucas Moura, but the Brazilian was unable to bring it down cleanly and Antonio Adan was able to sweep up.
Sebastian Coates headed just wide from a Sporting corner soon after, before Matt Doherty had a volley blocked following Adan's tip from an Ivan Perisic cross.
Adan then nearly diverted a low ball from Harry Kane into his own net, but the ball bounced the other side of the post and Sporting escaped.
At the other end, Pedro Porro's whipped delivery was diverted narrowly over the top by Paulinho to the audible fear of the home fans.
And Tottenham supporters' worst dreams were realised when academy graduate Marcus Edwards opened the scoring for the visitors, wriggling away from Pierre-Emile Hojbjerg before finding the bottom corner from 25 yards.
Sporting thought they had a second when Coates converted from a corner, but he handled the ball in and was instead booked.
After a dreadful first half, Spurs got a better grip of the game at the start of the second and went close at the end of a quick breakaway, with Adan pouncing to stop Hojbjerg's cross reaching a ready and waiting Kane.
A frenzy from the resulting corner saw handball appeals against Porro waved away, while Adan beat away a fierce half-volley from Dier.
Son Heung-min was next to force Adan into a save with a shot from a tight angle, before former Wolves loanee Francisco Trincao lashed over from close range at the other end.
A deep cross from Perisic fell to Doherty just inside the Sporting box, and Adan once again saved their skins with a smart save at his near post.
Sporting nearly hit Spurs on the counter with Flavio Nazinho darting in behind and bringing a low sprawling save out of Lloris, before he somehow put the ball wide after the Frenchman spilled Mateus Fernandes' effort.
Tottenham nabbed an equaliser with ten minutes remaining when Perisic's corner was met by a leaping Rodrigo Bentancur, who rose above Adan to pounce home.
The hosts nearly went in front after Son's free-kick was nodded on by Dier and it just whistled past the onrushing Bentancur and past the post.
Dier again was inches away from putting Tottenham ahead in the final minute of regulation time, this time nodding Clement Lenglet's cross wide.
Lloris then tipped away Fatawu Issahaku's 20-yard strike, before Son's strike was pushed out by Adan and then blasted over by Bentancur.
With the last kick of the game, Kane tapped home from Emerson Royal's head back across goal to send Tottenham Hotspur Stadium wild - but after a lengthy VAR check, the England captain was judged to have been offside and Spurs were denied a famous win, with Conte sent off for his protests.
Tottenham Hotspur vs Sporting CP player ratings, Champions League
1. Tottenham Hotspur (3-4-3)
GK: Hugo Lloris - 5/10 - Spurs seriously lack a goalkeeper capable of playing from the back. Little to do in way of shot-stopping until late on.
CB: Cristian Romero - 5/10 - Played with perhaps too much aggression, but wasn't the worst offender of Tottenham's under-performers.
CB: Eric Dier - 4/10 - The crowd quickly got on Dier's back for losing too many duels and simply hoofing the ball up the pitch.
CB: Ben Davies - 5/10 - Made his usual runs up the touchline but to little avail.
RM: Matt Doherty - 5/10 - Made great runs but his technical levels let him down and he wasn't too solid defensively.
CM: Rodrigo Bentancur - 7/10 - Played with too little urgency in the middle of the park at times, but stood tall to notch in the equaliser.
CM: Pierre-Emile Hojbjerg - 5/10 - Looked rusty on his return from injury. Improved after the break but not by much.
LM: Ivan Perisic - 6/10 - Marshalled attacks with a calmness but not with dynamism.
RF: Lucas Moura - 3/10 - His chaotic nature harmed Spurs more than it helped them. Seemed on a different wavelength to everyone else.
LF: Son Heung-min - 5/10 - Lacked his finishing and dribbling boots but put in the hard yards.
CF: Harry Kane - 5/10 - Faded out of the game fairly quickly. Was a poor presser, though was cruelly denied a late winner.
Manager: Antonio Conte - 5/10 - Tottenham were far too passive in the first half but wisened up after the break.
SUB: Bryan Gil (71' for Doherty) - 6/10 - His quick feet and nimble movements caused Sporting problems.
SUB: Clement Lenglet (81' for Davies) - 5/10
SUB: Emerson Royal (81' for Lucas) - 4/10
2. Sporting CP (3-4-3)
GK: Antonio Adan (6); CB: Goncalo Inacio (7), CB: Sebastian Coates (8), CB: Matheus Reis (6); RM: Pedro Porro (7), CM: Manuel Ugarte (7), CM: Hidesama Morita (6), LM: Nuno Santos (6); RF: Marcus Edwards (8), LF: Francisco Trincao (6), CF: Paulinho (6)
Substitutes: Mateus Fernandes (5), Flavio Nazinho (6), Arthur Gomes (5), Fatawu Issahaku (5), Jeremiah St Juste (5)
Manager: Ruben Amorim - 7/10