No 8 seed Karolina Muchova moved into the second round of the Tokyo Open when Marketa Vondrousova retired on Monday morning at the Ariake Coliseum.

Muchova, ranked No 12, led 6-2, 1-0 when Vondrousova, ranked No 58, pulled out at the Ariake Coliseum on Monday night.

Karolina Muchova will play Australian Maya Joint next.

Tokyo WTA 500, other first-round results (Ariake Coliseum, hard, USD 1.064.510, most recent results first):

Moyuka Uchijima vs. Sofia Kenin

Wakana Sonobe vs. Nikola Bartunkova

Alina Charaeva vs. Jaqueline Cristian

Victoria Mboko vs. Bianca Andreescu

Leylah Fernandez vs. Maria Sakkari



Diana Shnaider vs. Dayana Yastremska

Anna Kalinskaya beat Suzan Lamens (LL): 6-3, 6-1

Maya Joint beat Viktorija Golubic (LL): 1-6, 7-6 (5), 6-2

McCartney Kessler beat Cristina Bucsa (Q): 3-6, 7-5, 6-3

Varvara Gracheva (Q) beat Xinyu Wang: 4-6, 6-3, 6-4

Eva Lys (Q) beat Katie Boulter (Q): 6-2, 6-1