Women's tennis world number one Serena Williams has been seen singing karaoke with friends in London ahead of Wimbledon. The 21-time Grand Slam winner is in the UK capital ahead of the grass court Grand Slam, which starts on 27 June.

Williams sang songs including; "What a Feeling" by Flashdance and "Shake it Off" by Taylor Swift as she took an evening off preparing for the tournament. The US star also revealed she was a big karaoke fan.

"I do karaoke all the time. I was actually on Snapchat one day and I saw Venus (Williams) at a karaoke bar and I was at a different one! So it's funny".

Williams will be hoping her preparations for this tournament are more successful than the Italian Open in May, where she made herself ill from eating dog food the night before facing fellow America Christina McHale in Rome. Despite being ill for most of the night, and updating fans on her Snapchat story, she still managed to see off McHale in straight sets.

Serena Williams gets sick from eating dog food, but still reaches Italian Open quarter finalsIBTimes UK

Williams is aiming for her 22nd Grand Slam at Wimbledon, which would bring her level with Steffi Graf's record haul. However she has lost her last two Slam finals, with Garbine Muguruza beating her at the French Open last month.