efe-epaMadrid

Australia's Nick Kyrgios on Wednesday advanced into the Brisbane International quarterfinals after struggling to defeat his fellow countryman Matthew Ebden.

Though suffering from a knee injury, third-seeded Kyrgios managed to beat Ebden 6-7(3), 7-6(5), 6-2 over two hours and 12 minutes in the tournament's second round

"It had a bit of fluid in there leading up to the singles, but it doesn't really hurt me when I move, only when I am straightening my leg. I am sure I will be fine," said Kyrgios, ranked world No. 21, following the match.

The 22-year-old is due on Jan. 5 to play Ukraine's Alexandr Dolgopolov, who won 6-1, 6-2 over Argentina's Horacio Zeballos.