Top seed Ons Jabeur needed just 73 minutes to advance while No. 3 Aryna Sabalenka blew a one-set lead and lost Tuesday at the bett1open in Berlin.
Jabeur rolled past Karolina Muchova of Czech Republic 6-3, 6-3 on the grass courts. The Tunisian racked up four aces in the win.
Russian Veronika Kudermetova recorded 10 aces to rally past Sabalenka 2-6, 7-5, 6-4 in two hours, 11 minutes. Fifth seed Garbine Muguruza of Spain also lost in straight sets to German Andrea Petkovic 7-6 (8), 6-4.
No. 2 Maria Sakkari of Greece easily advanced with a 6-3, 6-2 win over Leolia Jeanjean of France. Eighth-seeded Belinda Bencic of Switzerland also advanced in three sets over German Jule Niemeier.
Top-seeded Jelena Ostapenko grinded out a victory but three top seven seeds weren't as lucky on the grass in Birmingham, Great Britain.
Ostapenko needed three sets to dispatch Canada's Rebecca Marino 6-2, 5-7, 6-3 in two hours even.
However, No. 4 Belgian Elise Mertens, No. 5 Czech Petra Kvitova and seventh-seeded Alison Riske all lost. Mertens won the first set but lost to Catherine McNally in two hours, 34 minutes.
No. 6 Sorana Cirstea of Romania also advanced in three sets over Shelby Rogers.