The England striker struck in the 75th minute to cap a dominant performance from Spurs.

They will face either Hull or Beijing Guoan in the final on Friday.

There was added disappointment for the Hammers after losing Luis Boa-Morte early in the game following a challenge with Benoit Assou-Ekotto and there are fears his knee injury could be serious.

Both sides had opted to play strong sides, with Spurs fielding new signing Kyle Naughton in midfield while Defoe and Roman Pavlyuchenko were paired in attack.

West Ham, meanwhile, handed a start to on-loan Inter Milan midfielder Luis Jimenez with last season's top scorer Carlton Cole deployed as a sole striker.

Spurs were lively from the start as skipper Luka Modric struck an effort wide with less than a minute on the clock.

But West Ham were quick to counter as James Collins saw his deft header from a free-kick land in the hands of Carlo Cudicini minutes later before Naughton's low drive went narrowly wide for Spurs after he was sent through by Alan Hutton.

In the 14th minute Boa-Morte went down clutching his knee following the challenge by Assou-Ekotto.

The winger and had to be replaced by Mark Noble and was taken to hospital.

Pavlyuchenko was causing a number of problems for the Hammers defence and the Russian striker had Green beaten in the 16th minute only to see his curled effort rattle off the post.

Collins was unable get any direction on a header five minutes before the break before Modric failed to capitalise on a swift counter from Spurs as the Croatia international curled a shot harmlessly wide.

Robbie Keane replaced Pavlyuchenko for Spurs at the start of the second half while Scott Parker replaced Kieron Dyer for West Ham.

It was Spurs who continued to dominate possession after the restart and a beautiful flick over the defence from Keane found Defoe but the former Portsmouth striker's first-time volley was high and wide.

The Hammers had perhaps their best chance of the game in the 55th minute. Jimenez exchanged passes with Cole inside the area but the Chilean midfielder's close-range effort was deflected out for a corner.

Tottenham should have taken the lead soon after when Defoe picked up the ball just outside the area, shrugged off the attention of Collins to forge a clear sight on goal but hit his effort over the bar.

Keane broke in the 72nd minute before feeding a pass for Modric, whose shot was blocked by Green, but Spurs grabbed the winner three minutes later.

Defoe picked up the ball just outside the area before holding off Julien Faubert and despatched a low shot that crept under Green and into the back of the net.