Top seed Dominika Cibulkova suffered a surprise defeat at the Rosmalen Grass Court Championships on Wednesday as she was beaten by qualifier Antonia Lottner in a three-set thriller.
Little had been expected of world number 161 Lottner ahead of their first-round meeting in 'S-Hertogenbosch but she took advantage of Cibulkova's serving troubles to seal a 7-5 2-6 6-4 win.
Lottner broke the two-time Wimbledon quarter-finalist on four occasions to secure her first win on the WTA Tour and a second-round meeting with Evgeniya Rodina.
Four of the quarter-finalists in the Netherlands are already decided after victories for Carina Witthoeft, Lesia Tsurenko, Natalia Vikhlyantseva and Anett Kontaveit.
In Nottingham there was another qualifier celebrating after Kristie Ahn cruised past Magda Linette 6-3 6-1 in the Aegon Open second round.
Ashleigh Barty avoided a similar fate to Linette, though, as she only dropped three games in a comprehensive 6-2 6-1 win over Jana Fett, the Australian setting up a potential quarter-final with top seed Johanna Konta.
Wednesday also saw straight-set wins for Donna Vekic and Tsvetana Pironkova - the latter needing 77 minutes to dispose of Kurumi Nara 6-3 6-2.