MELBOURNE, Australia — The tennis court becomes a fun house mirror when the player across the net is Hsieh Su-Wei, the queen of the overhead drop shot, whose wicked spins, clever angles and two-handed shots from both sides can rattle her opponents.Naomi Osaka, a three-time Grand Slam champion, sighed audibly on Sunday when informed that her reward for fending off two match points against Garbine Muguruza was a meeting with Hsieh, who clinched her place in the quarterfinals while Osaka was struggling to solve the problem that was Muguruza.“She’s one of those players that, for me, if it was a video game, I would want to select her character just to play her,” Osaka, the 2019 champion, said. “Because my mind can’t fathom the choices she makes when she’s on the court.”Osaka, 23, added, “It’s not fun to play her, but it’s really fun to watch.”Hsieh, 35, is more accomplished in doubles, where she and her partner, Barbora Strycova, arrived at Melbourne Park as the top seeds and exited in the second round. A three-time Grand Slam champion in doubles, Hsieh had never advanced to the quarterfinals in singles in 37 prior Grand Slam singles main draw appearances.“She’s probably going to smash me on the court,” Hsieh said cheerfully. “I try to play my game, do my job, see what happens.”Hsieh has a resting happy face, but behind the smile lurks a steely competitor. She has played Osaka five times, and four of the matches have gone three sets, including Hsieh’s lone win, in the third round in Miami in 2019 when Osaka was the world No. 1.Asked what makes playing Hsieh such a challenge, Osaka said, “Have you watched her play?” She laughed. “It’s like, ‘What?’”She added, “I know that for me, whenever I play her I just have to expect everything.”The showdown between Hsieh of Taiwan and Osaka of Japan, is a study in contrasts. Osaka creates pace and Hsieh redirects it. Osaka is a marketing magnet who added Louis Vuitton, Tag Heuer and Workday to her endorsement portfolio ahead of the Australian Open. Hsieh has no sponsors, partly by design.“I’d rather stay simple,” said Hsieh, whose tournament routine of shopping for discounted tennis wear has been upended by the statewide lockdown instituted last week.As embodied by Osaka, the power game is in vogue. But Hsieh’s more refined style will never go out of fashion. She is an artist that turns convention on its head with an unusual vision that gives the court its shape, the way a Bundt pan gives shape to the batter poured into it.“I think she has incredible hands and incredible eyes,” said Serena Williams’s coach, Patrick Mouratoglou. “She sees the ball very early, seeing and anticipating a lot.”That’s why she has such an economy of movement, he added, “and why she’s so difficult to play.”For the past three weeks, the tricky job of preparing the crafty Hsieh for her matches has fallen to Andrew Whittington, who advanced to the semifinals in men’s doubles at the 2017 Australian Open and has cracked the top 200 in singles.On a sunny Monday on Court 17, hard against the tram tracks on the eastern periphery of the grounds, Whittington spent close to an hour feeding Hsieh the hard, flat, well-placed serves that are Osaka’s signature.Hsieh’s coach, Paul McNamee, instructed Whittington to hold nothing back. After Hsieh failed to get her racket on a ball to her backhand, McNamee sidled up to Hsieh and said she would be seeing that serve a lot from Osaka.Hsieh nodded solemnly. Seconds later, she lifted a ball off the court with her racket, turned her back to the net and hit a no-look rainbow shot back to Whittington, who could only laugh.McNamee described Hsieh as a free spirit and said: “You don’t want to box that spirit. You’ve got to let it rise and be free.”Laughing, McNamee added, “I’ve learned the joy of silence a lot working with Su-Wei.”During the last few minutes of the hourlong practice, Whittington fielded serves from Hsieh, including a few made underhanded. He was more prepared for those than the question she lobbed at him near the end of the drill.“Is my serve very slow?” she said.It was the rare instance when she wasn’t kidding around. Sensing Hsieh’s vulnerability, Whittington moved quickly to assure her that her serve is fine. Like the rest of the arrows in her quiver, it is deceptively sharp. Hsieh has put 71 percent of her first serves in play in this tournament.Hsieh’s authenticity, her guilelessness, is “what makes her so unique and so great to work with,” Whittington said.Whittington brought more tennis rackets to the hitting session than Hsieh, who generally travels with one. The ball finds the sweet spot on her racket with such regularity, McNamee explained, that Hsieh went three years without breaking a string.An entertainer who wields her racket like a magician’s prop, Hsieh is sorry that the lockdown will shut out fans through Wednesday — and perhaps longer.“I think I just stay the same, enjoy, try to be positive,” she said. “If I don’t win, I hope quarantine finishes very soon so I can go out to enjoy a little bit.”Even if Osaka comes away with the win, she doubts it will be enjoyable. In the third round of the 2019 Australian Open, Osaka defeated Hsieh, 5-7, 6-4, 6-1.It is not a pleasant memory.“I just remember having, like, so many emotions just because I felt like there wasn’t a lot of things I could control while I was playing her,” Osaka said.It is Hsieh’s greatest strength. She can make the best, most powerful players feel helpless.