Azarenka comes from set behind to beat Krunic in US Open pre-quarterfinals

Two-times Australian Open champion Victoria Azarenka came from a set behind against inspired qualifier Aleksandra Krunic to beat the Serb 4-6, 6-4, 6-4 on Monday to advance to the US Open quarterfinals.

Azarenka, who began the year as world number two and slipped to a 16th seed after dealing with foot and knee injuries, took a 3-0 lead in the first set before the Serb, ranked 145th, roared back and claimed the set.

Krunic, on course to graduate college with an economics degree this year, continued to press the Belarussian, coaxing 40 unforced errors in the two-hour 19-minute match but in the end Azarenka's power and experience proved the difference, Stuff.co.nz reported.

The match ended an enthralling run by the diminutive Serb, who won three qualifying matches, beat 27th-seeded American Madison Keys in the second round and third-seeded Wimbledon champion Petra Kvitova of the Czech Republic in the third round.

Azarenka will next play Russian 17th seed Ekaterina Makarova, who defeated Canada's Eugenie Bouchard 7-6, 6-4.

Azarenka said that Krunic played some amazing tennis, adding that the Serb has a great future. She also said that she thinks it is never easy to play someone one does not know and added that she just tried to stay positive and fight.