|Venue: All England Club Dates: 29 June - 12 July|
|Play: From 11:30 BST on outside courts and 13:00 on Centre Court and Court One|
|BBC coverage: across TV, radio and online with up to 15 live streams available. Read More: TV and radio schedules.|
Petra Kvitova began her Wimbledon title defence with a swift straight-set win over Kiki Bertens, but last year's runner-up Eugenie Bouchard is out.
Czech second seed Kvitova opened day two's play on Centre Court, as is traditional for the women's champion, and won 6-1 6-0 in only 35 minutes.
Canadian 12th seed Bouchard was beaten 7-6 (7-3) 6-4 by qualifier Ying-Ying Duan of China.
And third seed Simona Halep lost to world number 106 Jana Cepelova.
Romanian Halep, 23, a French Open finalist last year, went down 5-7 6-4 6-3 to the Slovakian.
Danish fifth seed Caroline Wozniacki had a straightforward 7-5 6-0 victory over China's Saisai Zheng and 18th seed Sabine Lisicki of Germany was a 7-5 6-4 winner over Australia's Jarmila Gajdosova.
Poland's Agnieszka Radwanska, the 13th seed and 2012 runner-up, joined the pair in the second round with a 6-3 6-2 win over Czech Lucie Hradecka.
Bouchard bows out
Bouchard's Wimbledon of 2015 is in stark contrast to her campaign at the All England Club last year, when she reached her first Grand Slam final.
The 21-year-old from Montreal, ranked 12th, suffered an abdominal injury at Eastbourne earlier this month and her loss to world number 117 Duan is her 12th defeat in 14 matches.
"I felt very unprepared for this match but I wanted to play no matter what," she said.
"After Eastbourne we did testing and I've got a grade two tear in my abs. It was probably not smart to play here but I couldn't pass on Wimbledon.
"I was taped and it felt OK and I was trying not to think about it, but I haven't practised that much so I felt my timing was very off.
"I'm going to take some time to heal and maybe not think about tennis for a little bit and then get back to it."
Halep loses match (and toenail)
Halep, a semi-finalist last year, became the highest seed to exit the tournament so far, in what has been a miserable few weeks for the Romanian.
She lost in the second round of the French Open earlier this summer and against Cepelova on Court One she was not only broken eight times, but also lost a toenail towards the end of the first set and needed treatment.
"I knew it would be a difficult tournament for me," she said. "I didn't expect to lose in the first round."
Kvitova dropped just one point on serve - with a double fault - and goes on to face Japan's Kurumi Nara.
"I was very nervous but when I was standing on the court, the people were clapping, the atmosphere was brilliant," said the 24-year-old.
"I am really glad how I played as well. Nerves are important, they are healthy. I like them. I was sick a few days ago but still played very well."
Kvitova was not the only seed to win in a hurry.
Germany's Angelique Kerber became the third player to win without dropping a game at this year's tournament, beating compatriot Carina Witthoeft 6-0 6-0.
The 10th seed, who won the Aegon Classic in Birmingham earlier this month, replicated the wins Venus Williams and Andrea Petkovic secured on Monday.
Before this year's championships there had not been a 6-0 6-0 scoreline - a so-called 'double bagel' - in the women's singles event for six years.
Kerber will now face Anastasia Pavlyuchenkova of Russia.
World number five Wozniacki, 24, had a minor scare early on in her win over Zheng, losing two of her first three service games to go 4-1 down.
But the two-time US Open finalist recovered and won 10 consecutive games to sweep aside her Chinese opponent and set up a second-round match against 83rd-ranked Czech Denisa Allertova.