Australian Open champion Stanislas Wawrinka has qualified for the ATP World Tour Finals, according to organisers Barclays.
It means the 29-year-old will join the already-qualified trio of world number one Novak Djokovic, French Open champion Rafael Nadal and newly-crowned Shanghai Masters winner Roger Federer in the London event next month.
Wawrinka qualified despite an early exit at the hands of Frenchman and beaten finalist Gilles Simon in Shanghai earlier this week.
It is the second time the Swiss has reached the season-ending finale.
"It was my dream and goal to qualify again this year after the great experience in 2013," he said.
"The atmosphere in London is one of a kind and it means a lot to me to be there together with the very best players of the world."
Japan's Kei Nishikori, US Open champion Marin Cilic, Czech Tomas Berdych and Milos Raonic of Canada currently occupy the remaining four qualification positions.