Top seed Ons Jabeur and French Open runner-up Coco Gauff both advanced to the quarter-finals of the Berlin WTA grass court tournament on Thursday.

Tunisian Jabeur saved a set point to snuff out the challenge of 169th-ranked American Alycia Parks 6-2, 7-6 (10/8) to set up a clash with Belarusian Aliaksandra Sasnovich as she targets a fourth semi-final of the season.

"The second set, she started to play much better, and I had to take my chances when I had the break," said Jabeur.

"It's tough, I should have taken my chances when I was serving. I knew if it was gonna be 6-5 it would be really tough for me. But I'm glad I stayed calm afterwards."

Jabeur, the world number four, won her first tournament on grass in Birmingham last year before reaching the quarter-finals in Wimbledon.

Eighteen-year-old Gauff, the seventh seed, dominated China's Wang Xinyu 6-0, 6-4 to set up a clash with Czech seventh seed Karolina Pliskova, a Wimbledon finalist last year.