The 19-year-old Briton powered her way to a commanding 6-2, 6-2 victory in Seoul and will now face either top seed Jelena Ostapenko or 186th-ranked Victoria Jimenez Kasintseva.
Raducanu stunned the tennis world when she emerged from qualifying to win the US Open last year, but she has struggled to build on that and her Grand Slam defence ended in the first round last month.
Raducanu, who reached a career-high 10th in the world in July but is now 77th, showed flashes of her Flushing Meadows brilliance of 2021 in beating the third seed Linette in 77 minutes.
Sixth-seeded Raducanu got off to a fast start, quickly winning the first four games and taking the first set 6-2. She continued to dominate in the second set and her race to the finish line was only temporarily held up when her Polish opponent required a lengthy medical timeout.Read more on timesofindia.indiatimes.com