ORDER OF PLAY - 3:30 P.M. START
ZHENG Saisai (CHN) vs.  Aryna SABALENKA (BLR)
Svetlana KUZNETSOVA (RUS) vs.  Belinda BENCIC (SUI)
[WC] Ons JABEUR (TUN) vs.  Petra KVITOVA (CZE
Not before 8:00 p.m.
 Ashleigh BARTY (AUS) vs.  Garbiñe MUGURUZA (ESP)
 Gabriela DABROWSKI (CAN) / Jelena OSTAPENKO (LAT) vs.  Timea BABOS (HUN) / Kristina MLADENOVIC (FRA)
 HSIEH Su-wei (TPE) / Barbora STRYCOVA (CZE) vs.  Barbora KREJCIKOVA (CZE) / Katerina SINIAKOVA (CZE)
China's Zheng Saisai, facing No.9 seed Aryna Sabalenka in Thursday's opening match, is one of three unseeded players through to the quarterfinals in addition to Svetlana Kuznetsova and wildcard Ons Jabeur.
Zheng is into her second career quarterfinal at Premier 5 level or higher, and the first of which also came in Doha - four years ago, in 2016. She boasts a 2-1 head-to-head edge against Sabalenka, after the pair faced off twice last summer - including in the final of the Premier-level tournament in San Jose, which was won by Zheng for her first career title.
Former World No.2 Kuznetsova was the oldest player through to the round of 16, and benefitted from a walkover from American Amanda Anisimova (GI illness), who was the youngest.
The 34-year-old is bidding for her third victory this week, not including the walkover, for the first time since she reached the final of the Western & Southern Open in Cincinnati last summer.
After runs to the last eight in both Adelaide and St. Petersburg, Belinda Bencic is bidding for her first semifinal of the season. She owns a 3-1 career head-to-head record against Kuznetsova, and the contest is a rematch from the second round of the event in St. Petersburg two weeks ago, which was won by Bencic, 7-6(4), 6-4.
Fresh off of her best career win in terms of ranking over World No.3 Karolina Pliskova on Wednesday, Tunisian wildcard Ons Jabeur looks for a second straight win over a Czech Top 10 player when she faces 2018 Doha champion Petra Kvitova.
Jabeur and Kvitova have played once previously - in a 6-4, 6-2 victory by Kvitova on her favored lawns of the All-England Club at Wimbledon last summer. The Tunisian is bidding for her fifth career win against a Top 10 player in the match, and second consecutive, after having lost her six previous matches against players of that ranking.
The final quarterfinal is the lone match to take place between two seeded players, as World No.1 Ashleigh Barty takes on No.11 seed and Australian Open runner-up Garbiñe Muguruza. The duo will be facing off for the first time in two-and-a-half years, having split two three-set meetings in 2017.