Unseeded Katie Volynets of the US moved into the quarter-finals of the WTA Thailand Open after a thrilling three-set win at Arena Hua Hin yesterday.
The 22-year-old American stunned fourth seed Tatjana Maria of Germany 5-7, 6-2, 6-2 to advance.
Volynets dropped the first set 5-7 but came back strong in the next two sets to secure her place in the last eight of the WTA 250 tournament.
Maria, 36, had seven aces but also committed seven double faults during the match.
"She has a lot of experience and for me it was a good win today," said Volynets.
"Overall I'm just enjoying my tennis. My coach helped me a lot and I am very happy for the win today," said Volynets after the match.
Volynets next faces the winner of the second round match between Anna Karolina Schniedlova of Slovakia and Wang Yafan of China.
In late Wednesday night matches, China's third seed Wang Xinyu, the world No.24, defeated Nao Hibino of Japan 7-5, 6-4.
She will play Kazakhstan's seventh seed Yulia Putintseva, who defeated Swiss world No.71 Viktorija Golubic 7-6 (7/0), 7-6 (7/1), in the quarter-finals.