Former world number one Karolina Pliskova will drop out of the WTA's top 10 for the first time in almost five years after her bid to retain the Eastbourne title was ruined by Camila Giorgi on Tuesday.
The fifth-seeded Czech was beaten 2-6, 6-2, 6-2 by Italian qualifier Giorgi in the first round of the Wimbledon warm-up event on England's south-coast.
French Open finalist Anastasia Pavlyuchenkova suffered a 6-1, 6-3 defeat against Latvia's Jelena Ostapenko.
Russia's Pavlyuchenkova lost to Barbora Krejcikova in the Roland Garros title match, having at last reached her first Grand Slam final at a record 52nd attempt.
Second seed Elina Svitolina held her nerve to beat French Open quarter-finalist Paula Badosa 4-6, 6-1, 7-6 (7/1).
Bianca Andreescu, seeded third, secured her first victory on grass since 2018, defeating Christina McHale 6-4, 2-6, 6-2.
Britain's Harriet Dart lost 6-2, 6-7 (5/7), 6-4 against Kazakh world number 21 Elena Rybakina, who beat Serena Williams at the French Open.