Spurs' opener came from Clint Dempsey, but it was a gift from Aleksandar Dragovic, the Austrian making a terrible mess of his attempted return header to his goalkeeper and letting Dempsey in, who rounded Yann Sommer with ease and rolled the ball into the empty net to put Spurs into the lead both in the game and on aggregate.
Basel soon roared back into the game, however - Mohamed Salah was looking dangerous, and he equalised for the hosts, drifting into the right channel and making up for a heavy first touch with an excellent toe-poke that deceived Brad Friedel to put the hosts back into an aggregate lead on away goals.
The home side were soon to have the lead proper though - just after the start of the second half, Aleksandar Dragovic atoned for his earlier error by smashing the ball into the net from a corner. Basel were now in a good position, although Tottenham still only needed one goal to thwart them.
Spurs were looking disjointed and were creating few chances, but with just over ten minutes left to play, Dempsey scored again, and it was yet another gift from the hosts. It was poor defending to let him get on the end of a long free-kick in the first place, but Yann Sommer really should have done better with his prodded effort, but instead the keeper could only palm it into the turf and into the net.
Basel began looking for a goal themselves, and could've had one when Marco Streller was released to go clean through late on, but Jan Vertonghen brought him down to earn himself a red card and leave Spurs with the prospect of playing extra time with ten men. Dragovic's resultant free-kick was blazed over, and after a brief tussle between the teams at the end following a challenge from Tom Huddlestone, the two sides went to extra time.
Basel almost scored early on in the first half with an absolute rocket from Mohamed Elneny, the Egyptian letting fly form fully thirty yards with a thunderbolt that beat Brad Friedel bur crashed off the outside of the post. Spurs had a few chances to break themselves, but with Adebayor isolated simply couldn't put anything together.
In the second half, Basel really began to force the issue with Spurs barely able to escape their own area. Alexander Frei had a great chance after some fine football from Basel, and his shot appeared to beat Friedel and be heading for the bottom corner of the net, but a heroic diving block from Michael Dawson diverted it away. Frei had another chance afterwards, but was poorly-positioned to turn the cross in and could only manage an awkward and tame effort straight at Brad Friedel with the goal gaping.
Emmanuel Adebayor had a late opportunity to win it at the last, but with Gylfi Sigurdsson and Clint Dempsey in support, the Togolese forward tried to take it through the middle himself and the move broke down. The two teams then headed to penalties to decide the game.
Spurs hadn't won a penalty shootout for 19 years - it was, unfortunately, a record that would continue. Tom Huddlestone's penalty was well-saved by Sommer, but Emmanuel Adebayor's effort was awful, high and wide, and Basel's penalty-takers were unerring in getting the job done. Tottenham now have the fun task of trying to hold their league campaign together with a depleted squad. Basel are in a European Semi-Final and can look forward to taking on Chelsea, Fenerbahce, or Benfica.