Heather Watson takes on world No 1 Serena Williams at Wimbledon

Britain's Heather Watson will take on 20-time Grand Slam champion Serena Williams in the third round at Wimbledon hoping for huge backing from the Centre Court crowd on Friday.

Watson, who has been coached by Argentinian Diego Veronelli since December 2013, has taken additional input from Greg Rusedski this year as she looks to bring more aggression to her game and will need to play the game of her life to overcome the world No 1.

Williams will be continuing her bid for a sixth Wimbledon and 21st major title. The American star and world No 59 Watson are meeting for the first time.

Sky Sports' tennis commentator Barry Cowan says Watson's chances of upsetting Williams are "none".

Listen to the audio by clicking on the play button below ...

Novak Djokovic and Maria Sharapova will also be targeting last-16 places, hoping to avoid the underdog trap that claimed two-time winner Rafael Nadal.

Nadal, a 14-time Grand Slam winner, was knocked out by German qualifier Dustin Brown in the second round on Thursday, the great Spaniard's fourth successive early loss at the All England Club.

Defending champion and top seed Djokovic takes on Australia's Bernard Tomic who he defeated in the quarter-finals in 2011.

The Serb is bidding to reach the round of 16 at Wimbledon for the seventh straight year.

Sharapova, the 2004 champion, tackles Romanian 29th seed Irina-Camelia Begu who before this year had never won a match at Wimbledon.

Sharapova's boyfriend Grigor Dimitrov, who made the semi-finals in 2014, opens play on Centre Court against French 21st seed Richard Gasquet, a semi-finalist in 2007.

Gasquet has a 4-0 record against Dimitrov.

Fourth seeded Swiss Stan Wawrinka, the French Open champion, faces Spanish veteran Fernando Verdasco.

US Open champion Marin Cilic meets US 17th seed John Isner with a 4-0 career advantage.

Nick Kyrgios, who knocked out Nadal in the fourth round in 2014, faces Canadian seventh seed Milos Raonic who won their quarter-final clash last year.

The grounds of the All England Club will fall silent today as the nation in paying tribute to the victims of the Tunisia terror attack.

Matches on the outdoor courts usually start at 11.30am but will now begin at 12.15pm, the All England Club said.

The minute's silence will pay tribute to the 38 people, including 30 Britons, who were killed by a gunman on a Tunisian beach a week ago.

Five facts on the fifth day of Wimbledon at the All England Club

• World No 1 Novak Djokovic continues the defence of his title against Australia's Bernard Tomic. He has not lost to an Australian player at Tour-level since 2006 and will hope to continue that streak against Tomic on Centre Court.
• Nick Kyrgios, who faces Milos Raonic for the second year in a row, and Tomic are two of the five Australian players through to the third round along with Casey Dellacqua, Sam Groth and Sam Stosur. This is the first time five Australians have reached the third round at Wimbledon since 1999, when Wayne Arthurs, Jelena Dokic, Lleyton Hewitt, Mark Philippoussis and Patrick Rafter reached this stage.
• US Open champion Marin Cilic will be hoping to continue his good fortune against American opposition when he takes on John Isner for a place in the last 16. The Croatian is on a 24-match winning streak against Americans, having not lost to an American player in over seven years - when he fell to James Blake at the 2008 Australian Open.
• Neither Santiago Giraldo nor Denis Kudla has reached the round of 16 before at a major so the winner of their third round clash will achieve their own Grand Slam milestone. Giraldo is also looking to become the first Colombian man in history to reach the last 16 at Wimbledon.
• David Goffin and Marcos Baghdatis are also looking to achieve landmark wins. A win for Goffin in their match would see him become only the fourth Belgian man in the Open Era to reach the round of 16 at Wimbledon, while Baghdatis is seeking his 300th Tour-level match-win and a place in the last 16 for the first time since 2008.

Click here for Wimbledon order of play on Friday.