Novak Djokovic maintained his remarkable unbeaten record at the China Open, beating Nuno Borges to secure his first win since reaching the Wimbledon semi-finals in July.

The 39-year-old former world number one struggled in the second set but came through to win 6-3 7-6 (7-2) for his 30th consecutive victory in Beijing, albeit in his first appearance at the event since 2015.

Djokovic revealed in August that he has been dealing with an underlying health condition that causes particular issues in hot, humid conditions for "the past couple of years" and was far from his best against Portuguese Borges.

During the second set, he used his racquet to help stretch his back between games and needed a medical timeout to receive treatment to his right shoulder.

But despite that, Djokovic battled to victory in one hour and 50 minutes to set up a second-round match against wildcard Bu Yunchaokete of China.

Playing in the tournament for the first time in 11 years, the Serb, a 24-time Grand Slam champion, is bidding to win the China Open for a record-extending seventh time.

Meanwhile, Great Britain's Katie Boulter is through to the second round in the women's draw with a straight-set victory over Mai Hontama of Japan.

Boulter, 30, claimed a 6-3 6-4 win and will now face Czech seventh seed Karolina Muchova in the next round.