BEIJING — Rafael Nadal and Andy Murray advanced to the second round of the China Open with straight-set wins Tuesday in back-to-back matches on center court.

Nadal needed little more than an hour to beat Paolo Lorenzi 6-1, 6-1, fending off two break points as he took time to get his serve under control in the first set.

The 2005 China Open champion, seeded second in Beijing, improved his first-service percentage from 42 to 85 in the second set.

Murray defeated Andreas Seppi 6-2, 7-5 in the next match, dropping serve once in the second set.

Murray, who took over the No. 1 seeding when Novak Djokovic withdrew from the tournament, is playing at the China Open for the third time. He reached the quarterfinals in his debut and then the semifinals.

On the women’s side, Petra Kvitova beat Chinese qualifier Wang Yafan 6-4, 6-1 to reach the third round. The Czech, who last week won the Wuhan Open, will next face defending China Open champion Garbine Muguruza.