His retirement from back-to-back home tournaments over the past two weeks, first in Hangzhou and then Beijing, had left fans in doubt over his ability to compete during the highly anticipated Chinese season. Wu, however, eased those concerns with a convincing win in his first completed match in over five weeks.

When a physically ready Wu hits with confidence, his game is entertaining to watch.

By firing seven aces and racking up 25 winners, Wu dominated 83rd-ranked Nagal with his trademark barrage of powerful serves and lethal forehands, clinching his first win on the Tour since a first-round victory over Serbia's Dusan Lajovic at last year's US Open.

The 24-year-old is eager to start anew, having recovered from surgery to repair his troublesome left foot following his appearance at last year's Asian Games in his home city Hangzhou, Zhejiang province.

"Indeed I've had more ups and downs than my peers in the beginning of my career, but I am still quite confident in my game when I am healthy," said Wu, who reached a career-high ranking of No 54 in May last year, three months following his ATP250 title run at the Dallas Open in Texas.

"Everyone around me, my family, my team and friends, they all trust that I can still play excellent tennis. I just need to take better care of my body and have more consistent training."

Joining Wu in the second round at the Shanghai tournament is teen sensation Shang Juncheng, who claimed a first Chinese ATP title on home soil at the Chengdu Open on Sept 24, and wild-card holder Zhou Yi.

Nineteen-year-old Shang, the current world No 51, rode his recent momentum to beat Coleman Wong of Hong Kong, China, on Wednesday to set up an eye-catching rematch against four-time major winner Carlos Alcaraz. Shang's only previous meeting with the Spaniard, who just won the ATP500 title in Beijing, was in the third round at this year's Australian Open, when Shang had to retire in the third set due to injury.

"I know that he has really good potential, really good tennis ... I'm going to prepare as best as I can (against him)," Alcaraz said of Shang's game at a pre-tournament news conference in Shanghai on Thursday.

Zhou advanced into the second round in Shanghai after his Japanese opponent Yoshihito Nishioka retired injured while leading 4-2 in the first set.

The never-before-seen Chinese contingent at the season's penultimate ATP Masters tournament has captured the attention of the world's best.

Serbian great Novak Djokovic, who is making his return to China after a five-year hiatus, said the fact that Chinese men have caught up with their more successful women's counterparts only helps grow the game internationally.

"Historically, woman's tennis in China has always had great success, particularly with Li Na, who won multiple Grand Slam titles and was a great champion. That has positively affected, in a great way, the growth of tennis in China," Djokovic said after completing an open training session with China's top men's ace Zhang Zhizhen on Wednesday.

"It seems like the future is bright for Chinese tennis in both the men's and women's game. I like to see that," said the men's record 24-time major winner.

"I was actually hoping that there would be a Chinese man to break to top 100, top 50 in the world, and now you have not just one, but several of those guys that are really playing some good quality tennis.

"I don't think that the dedication, or putting in the effort, was ever a problem (in China). I think the Chinese mentality is such that, when they are dedicated to something, you can see that working hard is not an issue here.

"It will be very interesting to see on the men's side, how the players will evolve. I think it can only go up, because of the good mentality and, I guess, the overall great investment in tennis. I'm really excited to see how Chinese tennis will grow in the future."