Azarenka quits French Open due to injury

Paris - Fifth seed Victoria Azarenka was knocked out of the French Open on Tuesday when she was forced to retire from her opening round tie with a knee injury.

Former world number one and two-time Australian Open champion Azarenka went down 6-3, 6-7 (6/8), 4-0 to Italy's world number 118 Karin Knapp.

Azarenka, semi-finalist in 2013, hurt her knee midway through the second set and required a medical timeout.

She saved a match point in the tie-break but after a second session of treatment in the decider, she called it quits.