Defending champion Caroline Wozniacki has qualified for the WTA Finals in Singapore, with Petra Kvitova also sealing her place in the season-ending showpiece.
Danish star Wozniacki downed Venus Williams in straights sets to land the trophy last year.
“I’m very happy to qualify for the WTA Finals,” said Wozniacki.
“Winning the WTA Finals last year was a huge accomplishment for me, and helped my confidence leading into this season.
“I look forward to coming back to Singapore to try and defend my title.”
Kvitova returns to the event for the first time since making a comeback from career-threatening injuries. The Czech won the event seven years ago and reached the final in her last appearance in the tournament in 2015.
She said: “It’s a huge honour to qualify for the WTA Finals again.
“It will be my first time back there since I came back to tennis so it means a lot to me and has always been one of my big goals for the season.
“I can’t wait to visit Singapore again, especially in the tournament’s final year there.”
Wozniacki and Kvitova join Simona Halep, Angelique Kerber and Naomi Osaka in the draw for the WTA Finals, with three spots still up for grabs.
Wozniacki claimed a maiden major title earlier this year by landing the Australian Open title and she is 13.00 to successfully defend her Grand Slam crown in Melbourne.
Kvitova is 21.00 to win the Australian Open outright and Halep can be backed at 9.50.