Caroline Wozniacki began her Hong Kong Open defence by thrashing Eugenie Bouchard 6-1 6-1, while top seed Elina Svitolina edged out Zarina Diyas in the opening round.
World number six Wozniacki retained the Pan Pacific Open title last month and needed less than an hour to overcome the first hurdle to repeating that feat in Hong Kong.
Bouchard staved off three break points in her opening service game but would fail to hold again in the match, the Dane winning the next 10 games in succession.
Although Wozniacki dropped her serve with the chance for a second-set bagel, she hit straight back to set up a second-round match with Lizette Cabrera.
Svitolina encountered a number of difficulties but eventually overcame Diyas 6-4 7-6 (7-2).
The Ukrainian claimed the first set despite falling 3-0 down and wasted two opportunities to serve out the second as Diyas forced a tie-break before eventually succumbing to the third match point faced.
Venus Williams breezed past Risa Ozaki 6-2 6-2 and Agnieszka Radwanska found the going similarly routine as she defeated Zhang Ling 6-1 6-2, but fifth seed Elena Vesnina fell to Luksika Kumkhum in straight sets.
There were also wins for Anastasia Pavlyuchenkova, Naomi Osaka, Jacqueline Cako and Jennifer Brady.
At the Linz Open, third seed Kiki Bertens and fourth seed Anett Kontaveit were dumped out of the opening round by Varvara Lepchenko and Mihaela Buzarnescu respectively, both in straight sets.
Top seed Magdalena Rybarikova did not suffer the same fate though as she dispatched Richel Hogenkamp 7-5 6-3, while Monica Puig let a one-set lead slip against Ajla Tomljanovic as she went down 3-6 6-4 6-1.