Victoria Azarenka is confident that Aleksandra Krunic has a "great future" ahead of her after the two went head to head in the fourth round of the US Open.

Azarenka grabbed a place in the final eight by securing a 4-6 6-4 6-4 victory over the 21-year-old at Flushing Meadows

"Aleksandra played great tennis, she has a great future ahead of her," said Azarenka after the match. "It's never easy to play someone you don't know. I tried to stay positive and do whatever I could to turn the match around. In the important moments I managed to do it well."

Azarenka will face Russia's Ekaterina Makarova in the final eight.