In the Toray Pan Pacific Open in Tokyo, defending champion Caroline Wozniacki will play World No.1 Garbiñe Muguruza for the sixth time. The Spaniard leads the head-to-head 3-2, though Wozniacki's only victory in a completed match came at the same stage of this tournament in 2014 by a 6-4, 2-6, 6-2 scoreline. The Dane also took their only meeting this year in the fourth round of Miami via retirement.
Both Muguruza and Wozniacki will be playing their seventh semifinal of the season. Wozniacki is 6-0 at this stage this year - but has gone on to lose each of those finals. Muguruza is just 2-4, but went on to take the title after both of her semifinal victories. Wozniacki is gunning for her 49th career final, while Muguruza is aiming for her ninth.
Wozniacki is also seeking her second career victory over a reigning World No.1, having sealed her first last month in the Toronto quarterfinals over Karolina Pliskova.
In Tokyo, Angelique Kerber and Anastasia Pavlyuchenkova will play the 10th edition of a rivalry that the German narrowly leads 5-4 to date. However, Pavlyuchenkova leads 4-2 on hard courts - with one of those losses coming via retirement - including their only previous meeting of 2017 in the Monterrey final, which the Russian took 6-4, 2-6, 6-1.
Both Kerber and Pavlyuchenkova will be contesting their third semifinal of 2017. The winner will make her first final at Premier level or above this year; Kerber is looking to make her 27th career final, and Pavlyuchenkova her 16th (of which four have been at Premier level).
In the KEB Hana Bank-Incheon Airport Korea Open in Seoul, No.1 seed Jelena Ostapenko is playing her fifth semifinal of 2017, and first since her shock Roland Garros title in June. Her opponent, Thai qualifier Luksika Kumkhum, is playing the second WTA semifinal of her career following Osaka 2014.
Kumkhum, best known for upsetting Petra Kvitova in the first round of the 2014 Australian Open, has compiled a 17-1 record since Wimbledon including two ITF $25,000 titles; in addition, she also won the 2017 Southeast Asian Games in Kuala Lumpur, having opted to play there instead of the US Open. A win over Ostapenko would mark her third career Top 50 win - in addition to the Kvitova victory, the Thai beat No.32 Madison Keys via retirement in the 2014 Osaka quarterfinals.
In Seoul, both Beatriz Haddad Maia and Richel Hogenkamp are making their debut in a WTA semifinal - and will face each other for a maiden final appearance. In their only previous meeting, in the first round of the ITF $25,000 tournament in Caserta in 2013, a 16-year-old Haddad Maia won 4-6, 6-0, 6-4 - and went on to reach her first final at that level, losing to Renata Voracova.
Haddad Maia and Hogenkamp are two of the 13 players to have broken the Top 100 for the first time so far in 2017. Haddad Maia hit the milestone in May after winning the ITF $100,000 event in Cagnes-sur-Mer; Hogenkamp followed in June after qualifying and reaching the second round at Roland Garros.
The final of the Guangzhou International Women's Open will be the first encounter between Zhang Shuai and Aleksandra Krunic. Zhang's only previous WTA final was also in Guangzhou in 2013, when she beat Vania King 7-6(1), 6-1 to win her maiden title; until this week, she had not reached a WTA semifinal since last year's Zhuhai Elite Trophy. Krunic will be playing her first final; hitherto, her biggest career final was the Bol WTA 125K event in June, which she won over Alexandra Cadantu.
Orders of Play
Toray Pan Pacific Open, Tokyo
Centre Court (starts at 12pm)
Anastasia PAVLYUCHENKOVA (RUS) vs Angelique KERBER (GER) 
Garbiñe MUGURUZA (ESP)  vs Caroline WOZNIACKI (DEN) 
Daria GAVRILOVA (AUS) / Daria KASATKINA (RUS) or Makoto NINOMIYA (JPN) / Renata VORACOVA (CZE) vs Andreja KLEPAC (SLO) / María José MARTÍNEZ SÁNCHEZ (ESP) 
KEB Hana Bank-Incheon Airport Korea Open, Seoul
Centre Court (starts at 12pm)
Kiki BERTENS (NED) / Johanna LARSSON (SWE)  vs Katy DUNNE (GBR) / Priscilla HON (AUS)
Not before 2pm
Jelena OSTAPENKO (LAT)  vs [Q] Luksika KUMKHUM (THA)
Beatriz HADDAD MAIA (BRA) vs Richel HOGENKAMP (NED)
Nao HIBINO (JPN) / Oksana KALASHNIKOVA (GEO)  vs Luksika KUMKHUM (THA) / Peangtarn PLIPUECH (THA)
Guangzhou International Women's Open, Guangzhou
Centre Court (starts at 12.30pm)
Elise MERTENS (BEL) / Demi SCHUURS (NED)  vs Monique ADAMCZAK (AUS) / Storm SANDERS (AUS) 
Not before 3pm
Aleksandra KRUNIC (SRB) vs [WC] Shuai ZHANG (CHN) 
Relive highlights of Angelique Kerber's first Top 10 win of the season over Karolina Pliskova.