02 February, 2018
Caroline Wozniacki: Australian Open champion wins St Petersburg opener
The Dane required 67 minutes to beat Russian Anastasta Potapova 6-0 6-1 to achieve the last eight.
Potapova, 16, the world number 235, won the 2016 Wimbledon young ladies' title.
Wozniacki, who beat Simona Halep on Saturday to win her first Grand Slam title, will next face Russia's Daria Kasatkina.