Russian qualifier Maria Timofeeva reached the last 16 of the Australian Open by defeating Brazilian Beatriz Haddad Maia, the No 10 seed, 7-6 (7), 6-3 at Melbourne Park.
Timofeeva, ranked No 170, will face Ukrainian Marta Kostyuk next.
Earlier in the tournament, the 20-year-old Russian won against French wildcard Alize Cornet (6-2, 6-4) and Dane wildcard Caroline Wozniacki (1-6, 6-4, 6-1).
Haddad Maia, ranked No 12, beat Linda Fruhvirtova (6-2, 3-6, 6-2) and Russian qualifier Alina Korneeva (6-1, 6-2) in the previous rounds.
Melbourne (Grand Slam), other third-round results (Melbourne Park, hard, USD 58.910.000, most recent results first):
- Elina Svitolina vs. Viktorija Golubic
- Iga Swiatek vs. Linda Noskova
- Jelena Ostapenko vs. Victoria Azarenka
- Oceane Dodin vs. Clara Burel
- Anna Blinkova vs. Jasmine Paolini
- Qinwen Zheng vs. Yafan Wang
- Anna Kalinskaya vs. Sloane Stephens
- Emma Navarro vs. Dayana Yastremska
- Storm Hunter vs. Barbora Krejcikova
- Magdalena Frech beat Anastasia Zakharova (Q): 4-6, 7-5, 6-4
- Coco Gauff (4) beat Alycia Parks: 6-0, 6-2
- Marta Kostyuk beat Elina Avanesyan: 2-6, 6-4, 6-4
- Mirra Andreeva beat Diane Parry: 1-6, 6-1, 7-6 (5)
- Aryna Sabalenka (2) beat Lesia Tsurenko (28): 6-0, 6-0
- Amanda Anisimova beat Paula Badosa: 7-5, 6-4