Top seed Magda Linette bowed out in the first round of the WTA Thailand Open 2024 at Arena Hua Hin in Prachuap Khiri Khan yesterday.
World No.108 Diana Shnaider of Russia knocked out the 37th-ranked Pole in three sets 6-4, 1-6, 6-1.
Linette won the Hua Hin tournament in 2020.
Shnaider will play the winner of the match between former world No.2 Paula Badosa of Spain and Thai wildcard Lanlana Tararudee in the second round.
Other seeded players moved safely through, including No.3 Wang Xinyu and No.5 Wang Xiyu, both from China.
World No.36 Wang Xinyu advanced after her US opponent Emina Bektas retired in the first set with Wang leading 5-2 while the 63rd-ranked Wang Xiyu eased past fellow Chinese Wang Qiang 6-1, 6-1.
In the day's other big upset, qualifier Dalma Galfi of Hungary stunned former world No.32 Ajla Tomljanovic of Australia with a 6-3, 6-0 victory.
Galfi will play Wang Xiyu in the second round.
In other first round matches yesterday, Nao Hibino of Japan downed Kamilla Rakhimova of Russia 7-6 (7/4), 6-0 and Viktorija Gulobic of Switzerland beat Laura Pigossi of Brazil 6-1, 6-2.
Today, Germany's fourth seed Tatjana Maria meets the Netherlands' Arianne Hartono and China's sixth seed Yuan Yue faces Australia's Arina Rodionova.