Emmanuel Adebayor did not get mad, he simply got ahead.

The Tottenham Hotspur striker was the target of sustained racist abuse from Internazionale supporters last night but delivered the perfect riposte when he scored in the first half of extra time to send his side through to the last eight of the Europa League. The silence which befell the San Siro will have seemed golden for Adebayor.

His goal continued Spurs' ambition of mining European silver this season, although this was a tie which very nearly got away from them. They got off the plane in Milan clutching a three-goal first-leg advantage but that was eroded in 90 fraught minutes, with extra time bringing relief rather than celebration for the visitors.

The racist chanting which greeted Adebayor – the Togo striker was subjected to monkey chants throughout the evening – taineted a match in which Tottenham became increasingly pale, the London club seeming an imitation of the team that dominated Inter in the first leg. Their venture Milan was meant to be a formality, an opportunity to take in oneof Europe's most famous stadiums on their way to the next round but it soon became unsettling.

Antonio Cassano put Inter ahead after 20 minutes, the 30-year-old getting on the end of a Rodrigo Palacio cross to head in from six yards. It was a goal which had been coming since the Italian striker had twice been denied by saves from Brad Friedel in a frenetic opening to the tie.

Spurs – who were without the suspended Gareth Bale – could still cling to their advantage and should have extended it before half-time but instead Adebayor was wasteful and chipped over.

The miss was compounded when first a goal from Palacio who slotted in a through ball and then a William Gallas own goal after the break swung the tie in Inter's favour.

Villas-Boas threw on Lewis Holtby and Aaron Lennon in a bid to give his team more impetus, but Inter continued to lay siege to the visitors' penalty area. Instead it was Inter who found another gear – Cassano's free-kick squirming through the Spurs wall and prompting Gallas to stick out a leg and poke the ball past Friedel.

That balanced the tie on aggregate and Inter nearly completed a remarkable comeback two minutes into injury time when Gallas missed a tackle on Esteban Cambiasso, only for the Argentie to shoot wide from 10 yards.

Spurs were a more convincing threat in extra time but there was still an element of surprise as Adebayor extended a leg to prod a shot into the net and leave the hosts needing two goals to go through. They certainly came close; first Ricardo Alvarez nodded home from Cassano's cross to make it 4-4 on aggregate and then Friedel called into action to thwart further efforts as time ticked on.

The Italians shelled the Tottenham penalty area with a series of high balls and corners in the final moments but the visitors dug in to survive. The ceasefire at the end of the tie was then met with understandable relief.