Novak Djokovic, Aryna Sabalenka and Naomi Osaka all progressed at the China Open on Friday, while Britain's Katie Boulter was eliminated after losing to Karolina Muchova.
Djokovic survived a difficult second-round test against Chinese wildcard Yunchaokete Bu in Beijing. The Serbian recovered from losing the opening set to win 4-6, 7-6 (7-2), 6-2 after almost three hours on court.
The victory extended Djokovic's unbeaten record at the China Open to 31 matches. He will now face either Alexander Zverev or China's Juncheng Shang in the quarter-finals.
Sabalenka also advanced in Beijing with a convincing 6-1, 6-3 victory over Mexico's Renata Zarazua. The world No. 2 controlled the match from the start and secured her place in the next round in just over an hour.
Osaka had a tougher route into the third round, overcoming Maria Timofeeva 6-3, 3-6, 6-3. The four-time Grand Slam champion recovered after losing the second set and produced a strong finish to seal the victory.
Boulter's China Open campaign ended with a 7-6 (7-3), 6-1 defeat to eighth-ranked Muchova. The British player made a strong start and led 4-1 in the opening set, but Muchova fought back to take the tiebreak before controlling the second set.
In Tokyo, France's Arthur Fils continued his run at the Japan Open by defeating second seed Frances Tiafoe 6-3, 7-5. Fils will next face Monaco's Valentin Vacherot in the quarter-finals.
The China Open and Japan Open are part of the Asian hard-court swing, with several leading players competing as the season moves toward its final stages. The China Open is a WTA 1000 event, while the Japan Open is among the tournaments on the autumn Asian swing.
With Djokovic, Sabalenka and Osaka still in contention, attention now turns to the quarter-final stages, while Boulter will look to regroup after another close encounter with Muchova.