ORDER OF PLAY
MAIN ARENA -- 11:00 a.m. start
CoCo VANDEWEGHE (USA) vs.  Ashleigh BARTY (AUS)
Not before 12:30 pm
[Q] Zarina DIYAS (KAZ) vs.  Barbora STRYCOVA (CZE)
[Q] Gabriela DABROWSKI (CAN) vs. Johanna KONTA (GBR)
Not before 5:00 pm
 Sloane STEPHENS (USA) vs. Donna VEKIC (CRO)
[WC] Victoria AZARENKA (BLR) vs. [WC] Kurumi NARA (JPN)
DOME -- 11:00 a.m. start
[Q] Eugenie BOUCHARD (CAN) vs. [Q] Alison RISKE (USA)
Alicja ROSOLSKA (POL) / Abigail SPEARS (USA) vs. Miyabi INOUE (JPN) / Chihiro MURAMATSU (JPN)
 Raquel ATAWO (USA) / Anna-Lena GROENEFELD (GER) vs. Nao HIBINO (JPN) / Oksana KALASHNIKOVA (GEO)
2017 US Open champion Sloane Stephens faces Donna Vekic in the first round of the Toray Pan Pacific Open, in a rematch of their opening-round Wimbledon encounter which saw Vekic claim the upset, in Stephens' first match after reaching the Roland Garros final. Stephens won their only other meeting, which took place in Strasbourg in 2016.
Two-time Australian Open champion Victoria Azarenka makes her first appearance at the event since 2014 by taking on wild card Kurumi Nara, in their first meeting. Former World No.1 Azarenka's best showings in Tokyo were back-to-back semifinals in 2010 and 2011 -- both times, she lost to the eventual champion (Caroline Wozniacki and Agnieszka Radwanska, respectively).
Ashleigh Barty of Australia and CoCo Vandeweghe of the United States won the US Open women's doubles title together two weeks ago, which was the first Grand Slam doubles title for either player. However, they will face off against each other in the first round on Tuesday. Vandeweghe won their only prior encounter, in Zhuhai last year by the scoreline of 6-3, 6-3.
Gabriela Dabrowski has had her most recent top-notch successes in doubles, as she is ranked No.11 in that discipline and has two Grand Slam mixed doubles titles to her name. But the Canadian has shown over the past fortnight that she is still a fiery singles competitor as well, qualifying for the singles main draw in Quebec City last week and repeating the feat in Tokyo. Dabrowski takes on former World No.4 Johanna Konta in the opening round of singles; Konta leads their head-to-head by 2-0.
Former World No.5 Eugenie Bouchard faces off against Alison Riske in an all-qualifier affair. Riske won their first match in 2010, but Bouchard has reeled off five straight wins over the American since that point. This will be their first meeting since the opening round of the 2015 US Open.