Maria Sharapova battled through a tough Centre Court opener against fast-rising French player Kristina Mladenovic on the opening day of Wimbledon.

Twenty-year-old Mladenovic put former champion Sharapova under intense pressure in the opening set before the class of the world number three began to tell, resulting in a 7-6 (7/5) 6-3 victory for the Russian.

Sharapova said: "I'm pleased with this performance. The first matches on grass at Wimbledon are always really difficult and my opponent played extremely well. I'm really happy to be in the second round now."

Fifth seed Sara Errani was smarting at becoming the first major casualty as she was upset by Monica Puig.

Italian Errani, who reached the semi-finals of the recent French Open before losing to eventual winner Williams, went down 6-3 6-2 to her 19-year-old Puerto Rican opponent.

Victoria Azarenka had an injury scare after hurting her knee in a fall on Court One.

The second seed, who has been a losing semi-finalist in each of the last two years, was a set and a break ahead of Portugal's Maria Joao Koehler when she fell awkwardly at the back of the court.

It appeared she had suffered a knee injury that might end her involvement in the tournament, but after a long period of treatment the Belarusian ploughed on and clinched a 6-1 6-2 win.

Eighth seed Petra Kvitova was given a minor scare as she was taken to three sets by Coco Vandeweghe,

Serbian 12th seed Ana Ivanovic rode out a testing opening set against France's Virginie Razzano before tying up a 7-6 (7/1) 6-0 win.

Uzbekistan-born American Varvara Lepchenko, seeded 26th, was a casualty as she tumbled to a 6-2 4-6 6-4 loss at the hands of Czech player Eva Birnerova.

Caroline Wozniacki turned on the style in front of the watching Rory McIlroy, her golf superstar boyfriend, as she dropped just two games in seeing off Estrella Cabeza Candela, while Marion Bartoli also made it through.

Exciting teenager Sloane Stephens added further to the hype surround her with a classy dismantling of Jamie Hampton, but she will not be joined in the last 64 by Yanina Wickmayer who lost to Vesna Dolonc, nor by Lucie Hradecka who crashed to defeat against Karin Knapp.

Ukraine's Lesia Tsurenko was the first player to reach the second round, posting an early 6-1 6-3 victory against Spain's Lara Arruabarrena-Vecino.

Among the lower-ranked seeds to go through on the first afternoon of the tournament were Czech Lucia Safarova, France's Alize Cornet, Spaniard Carla Suarez-Navarro and Romanian Sorana Cirstea.

Italian Flavia Pennetta awaits Azarenka in the second round after beating Britain's Elena Baltacha 6-4 6-1, while Serbian 16th seed Jelena Jankovic ousted another of the home nation's hopes as she defeated Johanna Konta 6-2 7-5.

There were also wins for Michelle Larcher De Brito, who faces Sharapova next, along with Ekaterina Makarova, Petra Cetkovska, Eugenie Bouchard, Bojana Jovanovski and Yaroslav Shvedova.

Camilo Giorgi needed the minimum sets to see off Manchester's Samantha Murray, Christina McHale got past Alexa Glatch and Anne Keothavong went down to Gabrine Muguraza in the day's other matches.