Tottenham's rollercoaster ride in the Europa League came to a dramatic end as they were beaten 4-1 in a penalty shoot-out against Basle.
Clint Dempsey put Spurs ahead before Mohamed Salah and Aleksandr Dragovic scored to put Basle on course for victory.
Dempsey took the tie to extra-time with just eight minutes of normal time remaining - but Tottenham's task was then made much harder by the injury-time dismissal of Jan Vertonghen. The Swiss side failed to make their numerical advantage count, but Tom Huddlestone and Emmanuel Adebayor both missed from the spot in the shoot-out and Basle scored all four of their penalties to progess to the semi-finials.
It had all started so well for Spurs as in the 23rd minute Vertonghen sliced open the Basle defence with a pass that left Dragovic flat on his backside and Dempsey rounded the goalkeeper before slotting in to an empty net.
Villas-Boas jumped for joy - but he was soon cursing his luck after Mousa Dembele's error allowed Basle to level. Mohamed El-Nenny intercepted a sloppy pass from the midfielder and worked the ball out wide to Marco Streller, who cut open the Spurs defence to find Salah - who poked the ball past Brad Friedel.
Basel were in from after 49 minutes when Friedel palmed Fabian Schar's header straight to Dragovic, who smashed in from close range. But Spurs were not finished yet and substitute Huddlestone delivered a well-crafted chip that Dempsey drilled under Yann Sommer.
Vertonghen made life tougher for his team when he tripped Streller as he ran through in the 90th minute and received a straight red card.
Basle dominated the first half of extra-time, with El-Nenny rattling the woodwork from 30 yards and Marcelo Diaz curling wide.
Spurs held on for penalties - but Huddlestone missed Tottenham's first spot-kick to give Basle the advantage and Adebayor then skied Spurs' third while Schar, Streller and Fabian Frei all scored.
Diaz was left with the chance to clinch victory and he made no mistake, firing home to Friedel's left.