The field is filling out for the WTA Finals at Singapore, as both Petra Kvitova and Caroline Wozniacki made their qualification official on Thursday.
Kvitova became the fourth player to qualify, joining Simona Halep, Angelique Kerber and Naomi Osaka, when Katerina Siniakova defeated Kiki Bertens in Beijing on Thursday. Kvitova, who has won five titles in 2018, will make her fifth trip to the year-end championships. She took the title in 2011, when the event was played in Istanbul.
Quickly following suit was Caroline Wozniacki, who defeated Anett Kontaveit to book her sixth trip to the year-end championships. Wozniacki is defending her title at Singapore. She owns a 13-8 lifetime record at the WTA Finals in her five previous appearances. She also reached the final in 2010, losing to Kim Clijsters in the final.
There are currently six players still in the hunt for the last three spots— Sloane Stephens, Elina Svitolina, Karolina Pliskova, Aryna Sabalenka, Kiki Bertens and Anastasija Sevastova. Of those six, only Sabalenka is still alive in Beijing. The Belarussian kept her winning streak alive by knocking off defending champion Caroline Garcia in three sets on Thursday.