Australian Open: Dark horse Agnieszka​ Radwanska gallops into fourth round

Melbourne: Sixth seed Agnieszka Radwanska`s turbocharged advance at the Australian Open hit a speed bump Saturday before the Pole defeated American Varvara Lepchenko 6-0, 7-5 to make the fourth round.

Radwanska has now doled out a dreaded 6-0 "bagel" to each of her three opponents at Melbourne Park this year, but had to battle through when Lepchencko lifted in a second set that lasted almost an hour.

The 25-year-old hired 18-time Grand Slam champion Martina Navratilova as her coach late last year and is looming as the tournament dark horse.