World number seven Karolina Pliskova's Wimbledon preparations suffered a setback in a 6-2 6-3 defeat by Magdalena Rybarikova of Slovakia in the opening round of the Nature Valley Classic in Birmingham on Monday.
The 29-year-old Rybarikova, who ended Pliskova's Wimbledon campaign last year in a three-set thriller, was in complete control from the start as she claimed the victory in just over an hour.
"Karolina is a great player, and I have a lot of respect for her," Rybarikova, the 2009 winner in Birmingham, said courtside.
"Today I don't think it was her best day, but it was all about served and returns and I was just better at that. That was the key.
"I put so many returns in, and maybe she was thinking about our last match in Wimbledon. It could have been a different result today, but I'm so happy that I won this match."
Rybarikova will face Kristina Mladenovic for a place in the quarter-finals after the Frenchwoman edged past Czech Katerina Siniakova 1-6 6-2 6-4.