Kiki Bertens became the first from the Red Group to reach the semifinals at the BNP Paribas WTA Finals Singapore presented by SC Global on Friday, outlasting an injured Naomi Osaka, who was forced to retire after the first set.

Top seeds and co-World No.1s Barbora Krejcikova and Katerina Siniakova made a winning start to their debut campaign at the BNP Paribas WTA Finals Singapore presented by SC Global.

Relive the action from Singapore with WTA Insider's live blog.

Defending champion Timea Babos returned to the BNP Paribas WTA Finals Singapore presented by SC Global semifinals alongside childhood friend Kristina Mladenovic, dropping just two games against Gabriela Dabrowski and Xu Yifan.

"Thankfully I know my body well, so I knew there was something not right." Caroline Wozniacki reveals she was diagnosed with rheumatoid arthritis before the US Open.

Elina Svitolina ended Caroline Wozniacki’s BNP Paribas WTA Finals Singapore presented by SC Global title defense, going undefeated in the White Group.

Former World No.1 Karolina Pliskova has spent her downtime watching the other round robin clashes at the BNP Paribas WTA Finals Singapore presented by SC Global, weighing in on what makes the women's game so exciting.

Catch up as Elina Svitolina beat Caroline Wozniacki 5-7, 7-5, 6-3.

Karolina Pliskova claimed her first win in four meetings with Petra Kvitova at just the right time, earning a straight-set victory to become the first player to advance to the semifinals of the 2018 BNP Paribas WTA Finals Singapore presented by SC Global.

Western & Southern Open champion Kiki Bertens remained optimistic about her chances to make the semifinals at the BNP Paribas WTA Finals Singapore presented by SC Global, previewing her clash with Naomi Osaka on Friday.