With their mettle tested in tough opening wins, Chinese players have swung into action the hard way at the Australian Open, with the early examinations of their match-winning credentials bracing them for the challenges that lie ahead in Melbourne.

China's up-and-coming aces Shang Juncheng and Bai Zhuoxuan had to overcome tricky first-round matches at the Melbourne Park to earn their confidence-boosting tickets to the second round at the season-opening Grand Slam.

As the youngest among all Chinese qualifiers for the singles main draw, 20-year-old Shang proved his blend of youth and grit could make up for his lack of years by outlasting seasoned former top-10 Roberto Bautista Agut 3-1 on Monday to reach the second round of the Australian Open for a third time in his budding career.

Despite a second-set scare, Shang hit 63 winners to stun the 37-year-old veteran 6-4, 6-7 (2), 6-4,6-0 in two hours and 52 minutes on Court 8 to announce his comeback at his favorite major tournament, where he had to retire midway through his opening-round match last year, due to a bone fracture in his right foot.

"It wasn't an easy match, with quite a few ups and downs," Shang said after securing his fourth career win at the AO and seventh overall across the four majors.

"He's a very experienced opponent, having played on the professional tour longer than I've played the game in my entire career. So going against his finesse, I thought my advantage would be my speed and rhythm."

Shang's game plan worked in the end.

After conceding the first set out-gunned by Shang's rapid-fire winners, the Spanish former world No 9 hit back, winning a tense second-set tiebreak to draw even, silencing the vocal Chinese crowd cheering for Shang.

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The Chinese prodigy with a pint-sized frame will never be a power-hitter, but he used his quick feet and tactical variety to wear out Bautista Agut in the third set, sealing the fourth set in rampant fashion — 6-0.

"I had a couple of mistakes in the second set, giving up some points too easy and losing my cool at tough moments," Shang reflected.

"I did a much better job in the third and fourth sets, regaining the momentum with my serve and my baseline strokes.

"The strong support of the crowd was also a really big help, providing me with immense positive energy so I enjoyed playing and was extra motivated to go for each point."

Shang, who's climbed to world No 233 on the live ATP rankings with the win, will face 75th-ranked Botic van de Zandschulp of the Netherlands in the second round.

After undergoing the first surgery of his career to treat his foot injury in March last year, Shang spent six months in rehab and took a nosedive in the rankings, plummeting to No 253 at the end of last season from a career-high No 47 in October 2024.

Now with a series of solid wins behind him, including two victories in his pre-AO warm-up at the ATP250 Hong Kong Open, Shang's supporters are convinced that the once resilient teen prodigy, who's kept many of the "youngest" records for Chinese tennis, is coming back stronger.

"I am healthy again and really looking forward to gauging my game up against the world's best on the biggest possible stage here," said Shang, who became the youngest Chinese man at 19 to crack the top-100 in May 2024.

Sharing the spotlight with Shang in the women's draw was world No 702 Bai Zhuoxuan.

Virtually unknown to international fans, Bai introduced herself on the major stage by upsetting former major finalist Anastasia Pavlyuchenkova of Russia in her first-round challenge on Sunday.

Fighting through three qualifying rounds to make it to the main draw, Bai, who has been dubbed the "White Whirlwind" by Chinese fans, served up proof of her game by edging out the 2021 French Open finalist 6-4, 2-6, 7-6 (10) in a grueling two-hour-and-43-minute seesaw battle at the Kia Arena.

Although unfamiliar to most of the local crowd, Bai's scintillating form at the Melbourne Park has not come completely out of the blue as the 23-year-old had already left her mark on the major stage in 2023, when she broke into the second round at Wimbledon in her Grand Slam main draw debut.

Now after shocking another world-class opponent at a major, Bai has once again staked her claim to the Grand Slam courts. Without any concerns physically, Bai said she felt more confident than ever after recovering from multiple injuries on her lower back and right foot.

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"Perhaps I would've won my first match at the AO a bit earlier (if not injured), but it's never too late to win at a major," said Bai, who had to take a year-and-a-half break before returning to competition in fall last year.

Her drop in rankings won't be a problem as long as she trusts her game, Bai said, adding that she's grown more passionate about the sport than before.

"To be healthy again and play the sport at the highest level, I feel like I love tennis more and trust myself more," said Bai, who is up against Belarusian world No 1 Aryna Sabalenka in the second round.