Alli put Tottenham ahead from close range in the first half and the England midfielder doubled their lead with a fine solo effort after the interval.
Lacklustre Madrid were run ragged on their first ever appearance at Wembley and Christian Eriksen delivered the knockout blow to ensure Zinedine Zidane’s side won’t be wishing for a return to the English national stadium anytime soon.
Cristiano Ronaldo’s late strike was no consolation for the 12-time European champions, who hadn’t lost at this stage of the tournament since October 2012.
With two games still to play in Group H, Tottenham’s first ever win over Real means they are guaranteed to reach the knockout phase and, just as significantly, it should give them genuine belief they can mount a serious challenge for the trophy.
After an erratic start to the season, this was Alli’s coming of age party as the 21-year-old bossed the midfield on his return to European action after a three-match ban.
“It gives great belief and confidence to everyone because it’s a great result and we are in the next stage of the Champions League but it’s so important now to keep feet on the grass,” Spurs boss Mauricio Pochettino said after a win that ranks among the finest in his club’s history.
While Tottenham were in dreamland, Madrid’s shambolic display, coming after a shock La Liga defeat at minnows Girona last weekend, will add to the pressure on Zidane as he struggles to handle the first major test of his coaching credentials.
Real were unable or unwilling to match Tottenham’s intensity and Zidane said: “In all aspects Tottenham were superior.
“We are going through a bad moment. We have to keep our heads high.”
In the build-up to the match, Tottenham defender Jan Vertonghen had bragged he wouldn’t swap Harry Kane for even Ronaldo.
Kane buzzed around the Madrid defence with real menace and his driven pass to Kieran Trippier gave the right-back the chance for an audacious volley that flashed wide of the far post.
Despite losing Belgian defender Toby Alderweireld to injury midway through the half, Pochettino’s side were dictating the tempo and their vibrant start was rewarded in the 27th minute.
Eriksen’s pass picked out Trippier’s run and, with Madrid’s appeals for offside falling on deaf ears, the defender whipped over a low cross that picked out Alli, who got in front of the Madrid defence to stab home.
– Sublime style –
Ronaldo was largely anonymous for much of the first half and he spent more energy gesticulating to the referee and his team-mates than leading a Real revival.
When he finally had a sight of goal, the Portugal forward wasted the opportunity with a low shot straight at Tottenham goalkeeper Hugo Lloris.
Marcelo, surging away down the left edge of the Tottenham area, almost bagged a equaliser immediately after the interval when the left-back’s cross-shot forced Lloris into action.
But Real remained fatally flawed at the back and Alli took full advantage to double Tottenham’s lead in sublime style in the 56th minute.
Taking possession 25 yards from goal, Alli weaved his way past Madrid’s leaden-footed defence, working enough space on the edge of the area for a powerful strike that deflected in off Real captain Sergio Ramos.
With Zidane’s team now forced to chase the game, Tottenham were able to pick them off with a lethal counter-attack in the 65th minute.
Kane was the catalyst with a perfectly-weighted pass into Eriksen’s path and the Dane did the rest, clipping a nonchalant finish past Kiko Casilla to spark wild celebrations from the disbelieving Tottenham fans.
Ronaldo got one back with a deflected 80th minute effort, but it was far too late to salvage a futile night for Madrid.
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