Nadal, Li advance at China Open

Petra Kvitova of Czech Republic hits a return to Sara Errani of Italy during their women's singles match at the China Open tennis tournament in Beijing, Oct 2, 2013. [Photo/Agencies]

Elsewhere, No 8 seed Jelena Jankovic of Serbia looked headed for a straightforward win as she led 6-3, 3-1 but had to grind out a 6-3, 5-7, 6-3 win in two and a half hours against Kazakhstani qualifier Galina Voskoboeva.

No 3 seed Agnieszka Radwanska of Poland cruised past American Madison Keys in an hour and 15 minutes 6-3, 6-2.

"I played her at Wimbledon a few months ago, so I kind of knew what to expect, especially the big serve," Radwanska said. "We played a really long three-set match there. She was really serving unbelievable. So I knew I had to stand two steps backwards to reach that serve. But I don't think her percentage of first serves was as good as the matches before - it was a little bit easier for me today."

"But she's one of the youngest talented players coming out. Last year I was asked me to name which of the players can be the most dangerous to the top seeds, and I actually said it's Madison Keys, because she can play very good tennis. In a couple of years we're going to see her more often."

Earlier, Andrea Petkovic of Germany followed up her first round upset over Victoria Azarenka with a 4-6, 6-4, 6-1 win over two-time China Open winner Svetlana Kuznetsova.

Li, Serena cruise on, Venus out at China Open

Nadal makes winning start at China Open