Agnieszka Radwanska believes that she had to produce her best tennis to defeat Varvara Lepchenko to secure her place in the fourth round of the Australia Open.

The number six seed stormed out of the blocks to take the first set 6-0, but the 28-year-old battled back in the second to make life difficult for the Pole.

However, Radwanska displayed her quality in the crucial moments of the third set to take it 7-5 and win the match.

She told reporters: "I really had to play my best tennis to beat her, I had to prepare very well. I started well and then she started playing better in the second set. Winning in two sets is very important."

Radwanska will play the winner of the match between Camila Giorgi and Venus Williams in the next round of the competition.