Polish star Agnieszka Radwanska advanced to the Shenzhen final with a straight sets win over AnnaLena Friedsam on Friday and in the process secured the world No. 4 spot, committing Maria Sharapova to a 5-8 seeding at the Australian Open.

Radwanska, who capped a tremendous end to the season last year with a maiden title triumph at the WTA Finals, has unseated Sharapova from the No. 4 position meaning the Russian could face Serena Williams in the last-eight at the Australian Open later this month should the draw place them in the same quarter. Sharapova and Williams faced off in the Melbourne final last year.

With five of the world’s top-six all retiring from or withdrawing before their opening matches in 2016 this week, placing doubt on their readiness for Melbourne, Radwanska is considered one of the main contenders for the grand slam Down Under and her No. 4 seeding there is another welcome boost for the Polish 26-year-old.

Against Friedsam, Radwanska suffered a brief blip in the second set when she led 2-0 before getting pegged back by the German. But the crafty Krakow-native was in command in no time, wrapping up a 6-2, 6-4 victory to set up a final date with world No. 97 Alison Riske of the United States.

“Reaching the final here is great preparation for the Australian Open, and that’s a good projection too,” Radwanska said after being told of the ranking news. “First I’ll focus on winning here in Shenzhen, and then I’ll just try to play the same tennis in Sydney and in Melbourne.”

Over in Brisbane, ex-world No. 1 Victoria Azarenka blasted into the final, ending the surprise run of 20-year-old Samantha Crawford with a 6-0, 6-3 thumping. Azarenka takes on German No4 seed Angelique Kerber in the final on Saturday.