Wimbledon: Serena Williams Survives Scare, Novak Djokovic & Maria Sharapova Cruise

Serena Williams set-up a Wimbledon last-16 showdown with sister Venus on Friday after surviving a major scare as Novak Djokovic and Maria Sharapova eased into the second week.

Top seed Serena, bidding for a sixth Wimbledon title and already halfway to a calendar Grand Slam after wrapping up the Australian and French Opens, defeated unseeded Briton Heather Watson 6-2, 4-6, 7-5 in a Centre Court thriller.

Watson, the world number 59, served for the match at 5-4 in the final set after being a double break up but her nerve failed her against the 33-year-old American she idolised as a child.

"I've had some tough losses but that was probably my toughest match playing Heather in front of her home crowd," said Serena, who is chasing a 21st Grand Slam title.

"She played unbelievable and really I think she should have won the match."

Venus, also a five-time champion and playing in her 18th Wimbledon, reached the fourth round with a 6-3, 6-2 win over Serbia's Aleksandra Krunic.

Serena will face her 35-year-old sister on Monday for the first time in a Grand Slam since beating her in the 2009 Wimbledon final.

"We have a lot of respect for each other," said Venus. "There's no easy points when we face each other."

Watson admitted her big chance had passed her by.

"I was two points away from winning the match, so I am pretty disappointed," said the 23-year-old.

Top seed Djokovic made the last 16 for the seventh successive year by routing Bernard Tomic of Australia 6-3, 6-3, 6-3 on the back of 15 aces and 38 winners.

The Serb then faced a different challenge as he walked off Centre Court when he was asked to autograph the prosthetic leg of a wheelchair-bound fan.

"The gentleman gave me his artificial leg...I want to be politically correct about it," smiled the 29-year-old Djokovic who next faces South Africa's Kevin Anderson.

"I gave him my signature. I hope it will make him feel better."

Fourth seeded Maria Sharapova, the 2004 champion, made the last 16 with a 6-4, 6-3 win over Romania's Irina-Camelia Begu and goes on to tackle unseeded Zarina Diyas of Kazakhstan for a spot in the quarter-finals.

- Raonic, Dimitrov out -

Australia's Nick Kyrgios, who famously defeated Rafael Nadal in 2014 when he was ranked 144, avenged his quarter-final loss of 12 months ago to seventh seed Milos Raonic with a 5-7, 7-5, 7-6 (7/3), 6-3 victory.

The 20-year-old Kyrgios hit 34 aces and blasted 61 winners past the 2014 semi-finalist as he booked a fourth round clash with France's Richard Gasquet.

Kyrgios, seeded 26, faces another rematch in the fourth round against Gasquet after beating the Frenchman in a dramatic five-setter in the second round last year.

Gasquet, a 2007 semi-finalist and seeded 21, beat 11th seeded Grigor Dimitrov of Bulgaria for the fifth time in five meetings thanks to a 6-3, 6-4, 6-4 stroll.

Fourth seed Stan Wawrinka reached the fourth round with a 6-4, 6-3, 6-4 victory over Fernando Verdasco for his first win over the Spaniard in 10 years. The French Open champion will take on Belgium's David Goffin.

Goffin, the 16th seed, became only the fourth Belgian man to make the fourth round in the Open Era by defeating 2006 semi-finalist Marcos Baghdatis 6-3, 6-4, 6-2.

US Open champion Marin Cilic, the ninth seed, was locked in a titanic struggle with John Isner, the 17th seed, when their clash was halted for bad light at 9:20pm (2020GMT).

The two were level at 7-6 (7/4), 6-7 (6/8), 6-4, 6-7 (4/7), 10-10 after more than four hours on Court One with the winner to face American wildcard Denis Kudla, the world 105, for a place in the quarter-finals.

America's Coco Vandeweghe reached the last 16 at a Slam for the first time with a 6-2, 6-0 win over 2011 US Open champion Sam Stosur of Australia.

Stosur has yet to get beyond the third round at Wimbledon in 13 years of trying.

Vandeweghe will next face Czech sixth seed Lucie Safarova, who beat Sloane Stephens of the United States 3-6, 6-3, 6-1.

Teenager Belinda Bencic became the first Swiss woman into the fourth round since Patty Schnyder in 2007 when she defeated American qualifier Bethanie Mattek-Sands 7-5, 7-5 after trailing 5-1 in the first set.

Former world number one and two-time semi-finalist Victoria Azarenka made the last 16 with a 6-4, 6-4 win over France's Kristina Mladenovic and next faces Bencic.