Muguruza retains Monterrey title as Azarenka retires

Second seed Muguruza was leading the match between the two former world No 1s 6-1 3-1 when Azarenka decided she was unable to continue because of an injury to her right leg.

"It's unfortunate I couldn't give my best today, but I tried my hardest," a tearful Azarenka, who had not previously reached a final since the birth of her first child in December 2016, said at the presentation.

Azarenka received treatment on her leg during a medical time-out between sets, but it became apparent as the second set began that her movement had become significantly hampered.