The top-seeded Pole has dropped just nine games in her first three matches in the South Korean capital and cruised past her Russian opponent in 63 minutes.
Dushevina, who has not managed to take a single set off Radwanska in all four of their meetings, was hampered by a 49 per cent first serve rate and slapped down six double faults as she was broken five times.
Next up for Radwanska is Spaniard Lara Arruabarrena, who beat Korean wildcard Su Jeong Jang 6-0 6-4.
But Japan's Kimiko Date Krumm saw her run come to an end as Italian Francesca Schiavone battled back from a set down to win 4-6 6-4 6-4.
Against anyone else the 33-year-old Schiavone would be considered a veteran but she's almost a youngster compared to Date-Krumm, who at 42 continues to put younger players in their place on a regular basis.
Schiavone had too much for the Japanese player, however, and outlasted her opponent in two hours and two minutes to book her place in the last four where she will face third seed Anastasia Pavlyuchenkova.
The Russian proved too strong for Romania's Irina-Camelia Begu, booking her place in the semi-finals in 80 minutes with a 6-2 6-2 victory.