Spain's Garbine Muguruza successfully defended her Monterrey Open title on Sunday when Victoria Azarenka retired injured from her first WTA singles final in three years. Second seed Muguruza was leading the match between the two former world number ones 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 final since the birth of her first child in December 2016, said at the presentation. "I want to say thank you to my son Leo, who is not with me here. I would love him to be here to share this with me because it is special." The crowd responded with a chant of "Vika! Vika! Vika!". Muguruza's victory never looked in doubt and ensured that the record run of different women winning WTA titles this season would be extended to 16 tournaments. The former French Open and Wimbledon champion broke the pained Belarusian three times in the first set and again in the fourth game of the second. "It's a great feeling to come back and defend a title," Muguruza said in a courtside interview. "It's never easy." 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. Azarenka was grimacing and stretching after nearly every point and, after Muguruza broke for a 3-1 lead, the two-time Australian Open champion decided to call it quits. The Belarusian had entered the final full of hope after surprising top seed Angelique Kerber 6-4, 4-6, 6-1 in Saturday's semifinals. Azarenka had won her only previous meeting with Muguruza in the round of 16 at the Miami Open in April 2016, when she went on to win the title in her most recent final before Sunday. — Reuters