Sue Barker presents live coverage of the opening day's play at the All England Club, as this year's championships get under way in the men's and ladies' singles. The third Grand Slam event of the year on the hallowed grass courts is always one of the highlights of the sporting calendar, and the seeded players may be at risk of upsets as they acclimatise to the conditions after playing on clay for so long, although there were relatively few shocks on the opening day last year. Men's fifth seed Stan Wawrinka lost to Russia's Daniil Medvedev 4-6, 6-3, 4-6, 1-6, and enigmatic Australian Nick Kyrgios retired while two sets down to Frenchman Pierre-Hugues Herbert. Veteran American Venus Williams opened proceedings on Court One, seeing off Belgian player Elise Mertens 7-6 (9-7), 6-4 to set up a second-round women's singles meeting with Wang Qiang of China.