Author: Cole Paxton
Top seed Caroline Garcia and No. 7 seed Lucie Safarova fell on Friday.
Andreas Seppi also reached the final eight in Germany.
The Argentine could be forced from the game for up to six years.
No. 5 seed Carla Suarez Navarro and No. 8 seed Aryna Sabalenka also lost in Mallorca.
The Frenchman will face red-hot qualifier Bernard Tomic in the semifinals.
Robin Haase and Yuichi Sugita also fell to lesser opponents.
No. 5 seed Stefanos Tsitsipas earned his maiden victory as a seeded player, while Bernanrd Tomic notched his first main draw tour win of 2018 ...
2017 runner-up Natalia Vikhlyantseva also lost her opener.
Magdalena Rybarikova and Alison Van Uytvanck also won, but Camila Giorgi fell.
The veteran German ran past Mikhail Youzhny in the first round.
The seven-time Wimbledon champion is said to be recovering nicely from a pectoral injury.
Kiki Bertens also advanced, setting up a third round clash with Kerber.