LONDON: Serena Williams sank her sister Venus in a battle of the all-conquering Wimbledon titans on Monday as Maria Sharapova dug deep to join the world number one in reaching the quarterfinals.

The Williams sisters have won the title five times each out of the last 15 at the All England Club but it was Serena who triumphed in their first Grand Slam clash since the 2009 Wimbledon final.

Meanwhile, 2004 Wimbledon champion Sharapova, 2012 beaten finalist Agnieszka Radwanska and two-time Grand Slam winner Victoria Azarenka also booked their places in Tuesday’s quarterfinals.

All eight Wimbledon quarterfinalists from last year are out of the tournament, while Serena and Sharapova are the only two from the world’s top 12 who are still standing.

US duo Madison Keys and Coco Vandeweghe, Switzerland’s Timea Bacsinszky and Garbine Muguruza of Spain also made it to the last eight.

Serena secured her 14th win in 26 clashes with Venus and the sisters hugged at the net after the match on Center Court finished 6-4, 6-3.

Playing each other “definitely doesn’t get easier,” Serena said.

“I was out there, I thought, wow, I’m 33 and she just turned 35. I don’t know how many more moments like this we’ll have. I plan on playing for years but you never know if we’ll have the opportunity to face each other.”

As for the match, “it was really good for me to get it done in straight sets and just put this behind me and move forward,” she said.

The 20-time Grand Slam champion remains on course to completing the feat of holding all four majors at the same time, having the US, Australian and French Open titles under her belt.

Serena faces Azarenka, the 2012 and 2013 Australian Open champion, in the quarterfinals after the Belarusian 23rd seed saw off the in-form Belinda Bencic, on a career-high ranking of 22, 6-2, 6-3.

Sharapova endured her toughest test so far but still made it through to the quarterfinals with a 6-4, 6-4 win over Kazakhstan’s unseeded Zarina Diyas.

She faces Vandeweghe in the quarterfinals after the US world number 47 edged out Czech sixth seed Lucie Safarova, last month’s beaten French Open finalist, 7-6 (7/1), 7-6 (7/4).

Vandeweghe had never been beyond the third round of a Grand Slam before this year’s Wimbledon.

While Serena, Sharapova and Azarenka have 27 Grand Slam titles between them, there are no major winners at all in the bottom half of the draw, where 13th seed Radwanska is the highest-ranking player still standing after Caroline Wozniacki crashed out.

The Danish fifth seed, blew her chance to make the quarter-finals with a 6-4, 6-4 defeat to 20th seed Muguruza.

Wozniacki, who has been the world number one despite never having won a Grand Slam, was the only top 12 player left in the bottom half of the draw.

Wozniacki has now reached the fourth round at the All England Club five times without ever progressing.

Muguruza will face Bacsinszky for a place in the semifinals.

The Swiss 15th seed, who reached her first Grand Slam semifinal at the French Open, recovered from a terrible start to beat world number 48 Monica Niculescu of Romania 1-6, 7-5, 6-2.

Polish 13th seed Radwanska booked her spot in the quarterfinals with a 7-5, 6-4 win over Serbian 28th seed Jelena Jankovic.

Former world No.1 Jankovic had knocked out defending champion Petra Kvitova in the third round.

Radwanska faces 21st seed Keys in the quarterfinals.

The 20-year-old, an Australian Open semifinalist earlier this year reached the last eight with a 3-6, 6-4, 6-1 win over Belarusian qualifier Olga Govortsova.

Andy Murray slayed Croatian giant Ivo Karlovic to make the Wimbledon quarterfinals on Monday while controversial Australian Nick Kyrgios was under fire for ‘tanking’ in his last-16 exit.

British third seed Murray claimed a 7-6 (9/7), 6-4, 5-7, 6-4 win over 2.11-meters (six feet, 11 inches) tall Karlovic to book his place in the last-eight at the All England Club for the eighth successive year.

French 21st seed Richard Gasquet defeated Kyrgios 7-5, 6-1, 6-7 (7/9), 7-6 (8/6) in a controversial clash to avenge a second round loss to the temperamental Australian in 2014.

The 29-year-old, a semifinalist in 2007, will next face fourth seed Stan Wawrinka after winning a last-16 clash at the majors for just the third time in 19 attempts.

But Gasquet’s win was overshadowed by the latest controversy surrounding 20-year-old Kyrgios, the man who knocked out Rafael Nadal 12 months ago.

He tanked the third game of the third set — allowing Gasquet four uncontested points — after arguing with umpire James Keothavong over a code violation for swearing, a gesture which brought boos from the crowd.

If his actions are deemed to be an act of deliberately not trying, then he could face a heavy fine.

Kyrgios also argued with the official over the length of time he was taking to change his socks.

French Open champion Wawrinka defeated Belgian 16th seed David Goffin 7-6 (7/3), 7-6 (9/7), 6-4 to reach the quarterfinals for the second successive year.

Wawrinka is bidding to become just the fifth man to win Roland Garros and Wimbledon in the same year.

Pospisil became only the third Canadian man to reach the quarterfinals with a 4-6, 6-7 (4/7), 6-4, 6-3, 6-3 win over Serbian 22nd seed Viktor Troicki.

It was the world number 56’s third five-set match in four rounds and his first career comeback from two sets to love down.

Pospisil follows Robert Powell (1908, 1910 and 1912) and Milos Raonic (2014) as the only Canadian men to have reached the last-eight.

French 12th seed Gilles Simon reached the quarterfinals for the first time with a 6-3, 6-3, 6-2 defeat of Czech sixth seed and 2010 runner-up Tomas Berdych.

Simon, 30, will take on either seven-time champion Roger Federer or Spain’s Roberto Bautista Agut for a spot in the semifinals.

It will be his first last-eight spot at a major since the 2009 Australian Open.

US Open champion Marin Cilic made the quarterfinals for the second successive year with a 6-4, 4-6, 6-3, 7-5 win over unseeded American Denis Kudla.