By Amy Tennery
NEW YORK (Reuters) -Mexico's Renata Zarazua pulled off a stunning upset by beating sixth seed Madison Keys while twice major winner Barbora Krejcikova knocked out promising Canadian teenager Victoria Mboko, as the U.S. Open first round continued on Monday.
Keys finally claimed her maiden major at the Australian Open this year but produced an astonishing 89 unforced errors in the opening match of the day on Arthur Ashe Stadium as she fell to a 6-7(10) 7-6(3) 7-5 defeat.
Zarazua, the only
Mexican player in the U.S. Open main draw, saved seven break points across the match on Arthur Ashe Stadium for her first win over a top-10 player in a gruelling, three-hour and 10-minute affair.
"Coming into the match I was like almost crying because I was really nervous but I think the crowd made it so chill for me," she said. "I could hear some Mexican (fans) cheering so that was very nice."
She will hope to recreate the magic in the second round, where she faces Frenchwoman Diane Parry, who had no problems eliminating the twice Wimbledon winner Petra Kvitova 6-1 6-0 in her final professional match.
The Czech Krejcikova opened the action on Louis Armstrong Stadium in fine form after missing several months this year due to injury and easily navigated around Mboko 6-3 6-2, weeks after the 18-year-old's career breakthrough in Montreal.
She next plays Japan's Moyuka Uchijima.
Cameron Norrie advanced after American Sebastian Korda retired when trailing 7-5 6-4 and the Briton will next play the winner of a match between 28th seed Alex Michelsen and Argentinian Francisco Comesana.
U.S. tennis royalty opens up the evening programme at Arthur Ashe Stadium, as 45-year-old Venus Williams plays 11th seed Karolina Muchova as she continues her age-defying return to the court.
The seven-times major champion became the oldest WTA match winner since 2004 at the Washington Open last month and earned a wild card entry into the Grand Slam where she has twice lifted the trophy.
"I want to be my best, and that's the expectation I have for myself, to get the best out of me. And that's all any player can ask for," said Williams.
Her compatriot and mixed doubles partner Reilly Opelka will take to the court next, playing the second seed Carlos Alcaraz, who is in pristine form after winning his third 1000-level title this year in Cincinnati.
On Armstrong, the Norwegian former finalist Casper Ruud plays Austrian Sebastian Ofner while fifth seed Mirra Andreeva takes on American Alycia Parks in the late programme.
(Reporting by Amy Tennery in New YorkEditing by Toby Davis)
