Coco Gauff and Anna Kalinskaya reached the semi-finals of the Berlin grass court tournament on Saturday without having to play full matches as their opponents Ons Jabeur and Aryna Sabalenka retired.
With Viktoria Azarenka also winning her quarter-final prematurely the previous day when former Wimbledon champion Elena Rybakina retired with illness, the only completed last eight match at the event was Jessica Pegula's 7-6 (7-2), 3-6, 6-3 over Katerina Siniakova.
World number two Gauff saved two set points and needed 11 herself to win the first set against Jabeur 7-6 (11-9). The Tunisian then retired ill after being assessed by the trainer.
Kalinskaya was 5-1 up when Australian Open champion Sabalenka retired with what appeared to be shoulder and neck problems.
"I was happy with how I was able to play," Gauff said. "Of course, I send my best wishes to Ons. It's not the way you want to finish a match, especially with someone who is so nice on and off the court."
In the semis scheduled for later Saturday, Gauff plays Pegula while Kalinskaya faces Azarenka.
The busy schedule came because of rain the previous day when Azarenka advanced while Pegula led 4-2 in the first set en route to her first career semi-final on grass.
Another injury casualty at the tournament was reigning Wimbledon champion Marketa Vondrousova who also retired mid-match.
The final is on Sunday in the tune-up for Wimbledon which starts on July 1.
