Newly crowned US Open champion Juan Martin del Potro has become the fifth men's singles player to qualify for the prestigious Barclays ATP World Tour Finals, scheduled to take place at the O2 in London from 22-29 November.
He will join Roger Federer, Rafael Nadal, Andy Murray and Novak Djokovic.
Three spots remain open for the eight-player event.
Meanwhile, players who have qualified for the Sony Ericsson WTA year-ending championships in Doha are Dinara Safina, Serena Williams, Elena Dementieva and Caroline Wozniacki.
Four slots are still open for the eight-player event.
(Image via ATP World Tour website)