London: Tottenham marched into the League Cup semi-finals with a 2-0 win at bitter rivals Arsenal, but the north London derby was overshadowed as Dele Alli was hit by a bottle thrown from the crowd.
South Korea forward Son Heung-Min put Tottenham ahead in the first half of a fiery quarter-final clash.
Alli increased Tottenham’s advantage after half-time as they won at the Emirates Stadium for the first time in 10 visits dating back to 2010.
The England midfielder’s decisive contribution provoked a disgraceful reaction from an Arsenal fan, who threw a plastic bottle that cracked Alli on the back of the head in the 73rd minute.
Alli rubbed his head but appeared unharmed as he risked inflaming the situation further by gesturing towards the Arsenal fans to indicate the scoreline.
There also appeared to be other objects thrown by Arsenal supporters into the section occupied by Tottenham’s fans as the atmosphere turned toxic.
The shocking incidents came after a Tottenham fan was banned for four years after being found guilty of throwing a banana skin at Arsenal’s Pierre-Emerick Aubameyang when the teams met in an acrimonious clash earlier this month.
It continued a worrying trend of fan behaviour after the recent alleged racist abuse of Manchester City’s Raheem Sterling by a Chelsea supporter.
The unsavoury issues in the stands took the gloss off a mature Tottenham performance that underlined why Mauricio Pochettino has been installed as the bookmakers’ favourite to succeed the sacked Jose Mourinho as Manchester United’s next permanent manager.
Pochettino has yet to win a major trophy in his four-year reign at Tottenham, or in his previous jobs at Espanyol and Southampton.
But if the 46-year-old does take charge of United at the end of the season, once Ole Gunnar Solskjaer finishes his spell as interim boss, he remains in with a chance of leaving with silverware back in the Tottenham trophy cabinet.
Tottenham haven’t won a major prize since lifting the League Cup in 2008 and this will be their first semi-final appearance in the competition since they reached the final in 2015.
Just 17 days after Arsenal’s 4-2 Premier League win against Pochettino’s team, this was a welcome early Christmas present for Tottenham.
Arsenal, once again without the axed Mesut Ozil, had dominated the early exchanges, Aaron Ramsey drilling a low drive narrowly wide.
Henrikh Mkhitaryan should have put Arsenal ahead when he ran onto Ramsey’s deft pass, but the midfielder’s tame effort was saved by Paulo Gazzaniga.
Against the run of play, Tottenham gave a thrilling glimpse of their class as they snatched the lead with a lethal counter-attack in the 21st minute.
When Lucas Moura’s aerial challenge deflected the ball into Alli’s path, the Tottenham midfielder instinctively clipped a superb pass over the Arsenal defence.
Son anticipated the delivery with a perfectly-timed run behind the flat-footed Nacho Monreal and kept his nerve to slot a fine finish past Petr Cech.
Arsenal appealed in vain for a penalty when Lucas Moura nicked the ball away from Mkhitaryan as he prepared to shoot.
With Arsenal still protesting, Tottenham threatened to double their lead when Christian Eriksen broke away and teed up Moussa Sissoko, only for the midfielder to scuff a woeful shot high over the bar.
Ramsey was inches away from equalising when he met Iwobi’s cross with a volley that cannoned back off a post.
Arsenal’s profligacy proved costly as Pochettino’s men turned up the heat after half-time.
Pochettino went for the kill as he sent on Harry Kane for his first appearance in the tournament since 2015.
It was an inspired move as Kane played a key role in Tottenham’s second goal in the 59th minute.
When Cech miskicked a clearance straight to Kane, the Tottenham striker floated a superb pass to Alli, who beat the offside trap before clipping a majestic finish over the Arsenal keeper.
In the other quarter-final, Eden Hazard came off the bench to score Chelsea’s 84th minute winner in their 1-0 victory against Bournemouth at Stamford Bridge.
Manchester City and third tier Burton advanced to the last four on Tuesday.