Women's round-up: Barty begins campaign with win, Sharapova and Muguruza dumped out
Top seed Ash Barty completed a 6-4 6-2 win over Zheng Saisai in her opening match of this year's Wimbledon.
The French Open champion and world number one was given a decent work-out by the world number 43 Zheng before sealing victory in one hour and 16 minutes on Centre Court.
Barty's best at the All England club was a quarter-final spot a year ago.
The Australian will face Belgium's Alison Van Uytvanck in the second round.
"The first round is always tough and it took a bit of time to get used to conditions on that beautiful court which I have a lot of happy memories on. It took some time to adjust but I got there in the end," said Barty.
Former champions Maria Sharapova and Garbine Muguruza crashed out of Wimbledon in quick succession on Tuesday as big-name casualties continued to pile up, but twice winner Petra Kvitova made sure she did not join them.
Russian Sharapova, who ignited her money-spinning career by winning the title in 2004, was trailing 4-6 7-6(4) 5-0 to Pauline Parmentier of France when she retired injured.
The 32-year-old former world number one, now ranked 80, only returned from a right shoulder injury last month, although the problem this time was with her arm.
"I've had a history of a tendon problem in my left forearm and it flared up in the first set," she told reporters.
"This is not easy. I got myself into a good enough place to be part of this event and this is not what I wanted."
It was her second successive first-round exit at Wimbledon.
Spaniard Muguruza, champion two years ago, was knocked out 6-4 6-4 by Brazilian qualifier Beatriz Haddad Maia.
The 26th seed looked a shadow of the powerful player who beat Venus Williams to claim the title as she was outplayed by her 121st-ranked opponent.
Defeat continued a barren spell for the 25-year-old who has not been past the fourth round in any of the last five Grand Slam tournaments.
Czech Kvitova proved more reliable, easing into the second round with a 6-4 6-2 defeat of Tunisian Ons Jabeur, Africa's sole representative in the women's draw.
Sixth seed Kvitova, who won the title in 2011 and 2014, will play France's Kristina Mladenovic in the second round.
American ninth seed Sloane Stephens, who had crashed out in the opening round in the previous two years, breezed past Switzerland's Timea Bacsinszky 6-2 6-4 in her tournament opener.
Also advancing to the second round were Belgium's Elise Mertens, who beat Fiona Ferro 6-2 6-0 and China's Wang Qiang who eased past Vera Lapko 6-2 6-2. Lesia Tsurenko, the 32nd seed, fell 6-3 6-2 to Barbora Strycova.
Additional reporting from Reuters