Garbine Muguruza and Alize Cornet both fell at the first hurdle at the Lyon Open on Monday, going down to Linda Noskova and Camila Osorio respectively.
Having gone out in the first round at the Australian Open earlier this month, former world number one Muguruza did the same in France, suffering a resounding 6-1 6-4 defeat to 18-year-old Czech qualifier Noskova.
Third seed Cornet did not fare much better on home soil, capitulating after drawing level with Osorio as the Colombian triumphed 6-4 4-6 6-1.
The other seeds in action on day one at the WTA 250 event avoided the same fate, with fifth seed Anastasia Potapova beating Marina Bassols Ribera 4-6 6-1 6-2 and fourth seed Petra Martic fighting back to edge her two-hour battle with Kristina Mladenovic 3-6 6-3 7-5.
At the Thailand Open in Hua Hin, third seed Wang Xiyu was beaten in an all-Chinese meeting with Zhu Lin, while Wang Xinyu triumphed in straight sets against Joanne Zuger and Ukraine's Lesia Tsurenko eliminated Ysaline Bonaventure.
Fearless. Flawless.— wta (@WTA) January 30, 2023
Storming her way through qualifying, 18-year-old Linda Nosková hits her way past Muguruza 6-1, 6-4 to reach R2 in Lyon!#O6SML23 pic.twitter.com/Cg9TtL0JSy