The Barclays ATP World Tour Finals will stay in London for an extra two years until 2015, the ATP has announced.
The prestigious season-ending tournament moved to the O2 Arena in 2009 on a five-year deal and has been a huge success, with more than 750,000 spectators attending over the first three years and unanimous backing from the players.
An extension to the deal has been mooted since last year but has now been signed, and ATP executive chairman and president Brad Drewett said: "We are very happy to announce the extension of our original commitment in London for a further two years."
The tournament has been held in 14 different locations since its inception in 1970 and a number of cities were keen to take over from London, most notably Rio de Janeiro.
But the success of the tournament at the O2 and the calendar, which at the moment means there is no gap between the Paris Masters and the World Tour Finals, played into London's hands.
The players queued up to praise the event prior to the first match on Monday, with Andy Murray leading the calls for it to stay put.
The Scot said at the weekend: "If it does stay here then that's obviously good. I think they do a great job here, they put on an excellent show and everyone seems to enjoy it."
Roger Federer also backed London, saying: "If they move they'd better make sure it's a great place, one that makes sense for tennis and for the business and for our schedule. I'm sure that at this point the ATP is going to take the right decision here."
World number one Novak Djokovic was in favour of moving the tournament, though, believing London has had its turn.
The Serb said: "We are very happy but I am one of the players who supports the global promotion of this event and this sport in general so after five years here we should give the opportunity to other cities around the world because in that way we can promote the sport in the best possible way."