"I felt like I was playing a good game and I was in control from the beginning to the end," Swiatek said. "I'm happy that I was consistent. I didn't have ups and downs in the match, so it doesn't matter who I'm playing. If I play like that, I feel really confident."
"I think I always play quite well in China," said Ostapenko, a 2017 semifinalist in Beijing. "Finally, tournaments are back here and with a lot of fans, which I like a lot. After the US Open, I had a bit more confidence and I had really good preparation before that.
"Some matches during the year were close. I was losing them, but they were very close. I felt like at some point they have to go my way. It's working now."
Elena Rybakina avoided a huge upset as the former Wimbledon champion battled from a set and 4-2 down to claim 10 of the last 11 games against Russian 16-year-old Mirra Andreeva to prevail 2-6, 6-4, 6-1.
Brandon Nakashima beat Bernabe Zapata Miralles 6-1, 7-6 (3) and will play third-seeded Holger Rune in the second round, while Yoshihito Nishioka defeated Daniel Altmaier 6-4, 3-6, 7-6 (2) to set up a meeting with eighth-seeded Casper Ruud.
The Associated Press and Reuters contributed to this report.