Garbine Muguruza drew on her battling qualities to reach the quarter-finals of the Wuhan Open, while Karolina Pliskova eased through after qualifier Maria Sakkari claimed another scalp.
Top seed Muguruza will play Jelena Ostapenko in a battle of two grand slam champions in the last eight but the world number one was given a scare in a 6-2 1-6 6-4 victory over qualifier Magda Linette.
Pliskova started the week knowing she can return to the top of the rankings if she is crowned champion and Muguruza fails to reach the semi-finals, a scenario which remains a possibility after the third seed's 6-2 6-1 crushing of Wang Qiang.
Sakkari stunned Caroline Wozniacki on Tuesday and toppled 16th seed Elena Vesnina in the third round a day later, winning 7-6 (8-6) 7-5.
Ashleigh Barty beat fifth seed Johanna Konta in the second round and followed that up with a 4-6 6-0 6-4 success over Agnieszka Radwanska, while Caroline Garcia beat seventh seed Dominika Cibulkova in straight sets.
French Open champion Ostapenko defeated Olympic gold medallist Monica Puig and Ekaterina Makarova got the better of Simona Halep's conqueror Daria Kasatkina. Alize Cornet also made it through at the expense of Varvara Lepchenko.
MUGURUZA CONTENT AFTER SCRAPPING IT OUT
Muguruza lost only three points on serve in the first set and her forehand was firing on all cylinders, but Linette dictated a one-sided second set to level the match.
The Wimbledon winner, playing with a strapped up left thigh, saved three break points in the first game of the decider as Linette had her scampering around the court but it was the favourite who prevailed by claiming what was the fifth consecutive break.
Muguruza offered an honest verdict when asked about her performance.
The two-time major champion said: "I didn't really play my best tennis. I'm happy, of course. Maybe I didn't jump when I won, but I'm very happy. These are the matches, it sounds classic, but you fight, you go through, you get the victory, you feel pleased with yourself."
PLISKOVA WELCOMES 'EASY' WIN
Pliskova added a second Chinese scalp to her record this week as she followed up victory over Zhang Shuai with success at the expense of Wang.
The world number four, who will face Barty in the last eight, said: "It's just good to have these kind of matches in the year. Obviously you have tough matches, but sometimes you need an easy one as well. That was today.
"This was one of the best matches this year. No matter the opponent, no matter the tournament, I just felt great today. Maybe the match what I was playing yesterday quite helped me as well to go through the tough points and tough games. That's why I felt that good today."
SAKKARI AND BARTY MARCH ON
While Muguruza and Pliskova are names you would expected to see in the last eight, the same cannot be said of Sakkari.
The 22-year-old from Greece - making her debut in Wuhan and playing in the main draw of a Premier-level event for only the second time - shocked Wozniacki in round two and the world number 80 was not content with that upset.
Vesnina felt the full force of the outsider, who will take on Cornet at the quarter-final stage after breaking her rival five times to prevail.
Barty also marches on, the Australian outsider fighting back to defeat ninth seed Radwanska and reach her fifth quarter-final of the year.