Roger Federer has booked his place in the Barclays ATP World Tour Finals following his 15th Grand Slam victory.

Federer's epic five-set victory over Andy Roddick has ensured he will be among the elite eight-man field at London's O2 Arena in November.

The Swiss star joins Australian Open champion Rafael Nadal is having already qualified for the tournament.

Federer said: "It's great to be already qualified so I'm happy to be part of that elite group again, and challenging the other players in the round robin. It's going to be fabulous I'm sure, and I've only heard good things about the arena.

"I think it's great to have the event in London in a massive city like this. I think it's very fitting; this is one of the great tennis cities around the world. People in this country love sports and they love tennis."

Federer beat Roddick on Sunday to overhaul Pete Sampras' tally of 14 Grand Slam singles titles.

He has previously on the season-finale on four previous occasions.

The world's top eight players will compete in the final event of the ATP season between November 22 and 29. The tournament moves to London this year from Shanghai where it was known as the Masters Cup.

Briton Andy Murray will be hoping to compete on home soil in North Greenwich and he is also closing in on a spot following his run to the last four in SW19.

Roddick is, at present, sixth in the qualifying table. Novak Djokovic, Juan Martin Del Potro, Gilles Simon and Jo-Wilfried Tsonga are the other players currently occupying top-eight spots.

For the doubles event, Wimbledon champions Daniel Nestor and Nenad Zimonjic, and the pair they beat in the final, the Bryan twins, have become the first teams to qualify.