With less than a minute of normal time remaining, Spurs were heading out of the Europa League on away goals as Lyons protected the 1-0 lead obtained through Maxime Gonalons' first-half header.
Spurs had pressed and pressed in the second half but, just when it seemed Lyons were over the line, Dembélé arrowed a low shot into the bottom left corner from 25 yards. The home side were disconsolate, Spurs were exultant, their coaching staff leaping off the bench and towards the pitch, led by their head coach, Andre Villas-Boas. In the autumn of 2010, Bale scored a hat-trick against Inter in Milan and tore them apart in the return game. How he will relish the chance to repeat it in next month's last-16 tie.
He is not the only one. "If you go through against Lyons and then Inter, it puts you in a good place to win the competition," said Villas-Boas. "It will be extremely difficult [against Inter] but we approach the game to win it.
"Inter won the Champions League in 2010 and they represent a step up in terms of the competition we can face. It's a great, great fixture for us and I'm really happy to be able to play a game like this in this competition."
It was a result Spurs just about deserved and for the club, it was a sweet ending to a trip soured by the violence of Wednesday night. Three Spurs supporters were taken to hospital after they were injured in an attack on a city-centre pub, during which the assailants made Nazi salutes and threw missiles through windows.
If only Spurs could have mustered the desire at the start that they displayed at the end. In possession, they were ponderous and without the ball, they looked vulnerable. In the early stages, Kyle Walker looked especially uncertain.
Alexandre Lacazette had already put a free header wide before Lyons took the lead in the 17th minute. Lisandro Lopez drew the foul from Walker, Clément Grenier sent over the free-kick from the left for the unmarked Gonalons to head in at the near post.
Lisandro then steered wide after moving free of his marker in the 32nd minute as the visitors, 2-1 in front from the first leg, struggled to gain a grip on the match. Although Spurs had rarely threatened, they came very close to an equaliser just before half-time, when Lewis Holtby's low strike was pushed on to the post.
For the second half, Villas-Boas moved Bale into the centre, closer to lone striker Emmanuel Adebayor, and it made a significant impact. The visitors' confidence grew as they pushed forward, with Lyons happy to protect their advantage and play on the break.
After a rapid counter-attack in the 50th minute, Bale volleyed Adebayor's right-wing cross just wide from a wonderful position. Then, as Spurs advanced, they had a scary moment. Friedel presented a Lisandro cross to Lacazette, who tried to go around the goalkeeper, fell – and was annoyed to see referee Wolfgang Stark ignore his claim for a penalty. Spurs thought Aaron Lennon deserved a penalty when he tumbled trying to reach the loose ball; the referee did not.
Again, Bale troubled Vercoutre from distance. Substitute Clint Dempsey headed the winger's left-wing corner over the bar and Adebayor, displaying far more verve than he had in the first half, set up Dempsey for a chance with which he should have done better. Dembélé's late brilliance ensured Dempsey's error was irrelevant.
Man of the match Lisandro.
Match rating 8/10.
Referee W Stark (Ger).
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