Qualifier Sun extended her dream run at the All England Club on Friday as she beat China's Zhu Lin 7-6 (7-4) 7-6 (8-6) to set up a clash with British favourite Emma Raducanu.
She will be the huge underdog against the former US Open champion and will have to contend with a partisan Centre Court crowd, but the 23-year-old appears unfazed.
"I wasn't expecting to be here at this stage, but I've just been playing match-by-match. But yeah, here I am," she said.
The travelling life is the norm for professional tennis players these days but left-hander Sun was crossing the globe before even picking up a racket. So a venture to Centre Court will be just another place she can tick off.
Sun was born in the south of New Zealand to a Croatian father and Chinese mother and lived with her mum and grandmother in a small town with "more sheep and deer" than people.
Explaining her complicated early path to curious media on Friday, she said she then moved to Shanghai, before moving to Switzerland where she began life on the road as an up-and-coming junior tennis player.
"I didn't spend too much time there when I started playing more and more juniors," said Sun, who now resides in Geneva.
Prioritising her education, she then studied in the United States in Austin, Texas, studying political science, before focusing on her tennis career.
She made her Grand Slam main draw debut at the Australian Open after qualifying and also came through the Wimbledon qualifiers to book her debut at the grasscourt slam.
After knocking out Chinese eighth seed Zheng Qinwen in the first round, the 123rd-ranked Sun has gone from strength to strength to guarantee a paycheck of at least $504,000.
Not bad for a player whose career earnings to date, according to the WTA, are $464,000.
There are similarities between Sun and Raducanu even if their tennis careers have taken very different paths.
Raducanu's mum is Chinese, her dad Romanian and she was born in Canada and the British player has said in the past that the blend has helped her on the court. Likewise Sun.
"Chinese obviously from my mom's side, is very disciplined, hard-working. From my dad's side, Croatian, he's from the seaside, so very laid back and calm," she said.
"I guess that's a good combo. And then Swiss side is, like, neutral, yeah! From New Zealand I get that adventure side."
The last woman from New Zealand to reach the fourth round at Wimbledon was Ruia Morrison.
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