Tennis-Revitalised Azarenka downs Muchova to reach last eight

Muchova took a lengthy medical timeout and returned heavily strapped for the decider but unseeded former world number one Azarenka would not be denied and marched on to a last eight date with Elise Mertens.

Victoria Azarenka reached her first Grand Slam quarter-final in more than four years after rallying from a set down to beat Czech Karolina Muchova 5-7 6-1 6-4 in the fourth round of the U.S. Open on Monday. The 31-year-old twice Australian Open champion was broken three times in the opening set but 20th seed Muchova looked increasingly hampered by a problem with her upper left thigh on Louis Armstrong Stadium.

Azarenka, on a high after winning her first title for four years at the Western & Southern Open, took full advantage of Muchova's discomfort to whip through the second set and even up the contest. Muchova took a lengthy medical timeout and returned heavily strapped for the decider but unseeded former world number one Azarenka would not be denied and marched on to a last eight date with Elise Mertens.