Andy Murray will need stamina to handle Ivo Karlovic

If a mindset can be borrowed from another player, Andy Murray could do worse than glancing at how Roger Federer defused an explosive Sam Groth. Even when the Australian delivered the second heaviest serve ever seen at the All England club, Federer got to it. He failed with the return but it highlighted an often overlooked element of Federer's game: his ability to return serve.

Afterwards he was asked how he did it, but his answer shone no light on how to pick the spot where Groth’s ball would land, within a fraction of a second of release. His movement, patterns and reacting was the recipe said Federer, not altogether certain.

Speed merchant

Groth (27) is best known for the speediest serve in tennis history, a 163.4mph blur at an ATP Challenger event in Busan, South Korea, three years ago.

Saturday's smear may still be on the grass after he sent down a 147mph ace early in the opening set. Wimbledon hadn't seen anything that fast since American Taylor Dent sent down a 148mph serve in a 2010 loss to Novak Djokovic.

But Federer stoically accepted that patience was his ally with a 6-4, 6-4, 7-6 (7), 6-2 win putting him last on Centre Court today to face Spain’s Roberto Bautista Agut.

Murray may look and learn because his fourth round obstacle on Monday is the 6ft 10in Ivo Karlovic, who on Saturday became the first player in the recorded history of the game to hit 40-plus aces in three consecutive matches.

At 36, Karlovic seems only to be getting better in one aspect of the game. He will want short points, Murray to move him around court. Karlovic took two hours and 50 minutes and three tie-breaks to beat the 13th seed, Jo-Wilfried Tsonga, 7-6 (7-3), 4-6, 7-6 (7-2), 7-6 (11-9).

He added 41 aces to the 53 he struck in beating Alexandr Dolgopolov and 42 in the first round against the Swede Elias Ymer. In doing so the Croat took his tally to 136 to stay on top of the leaderboard for aces. But he has not beaten Murray in five attempts and last played him at Wimbledon in 2012.

“It will be a very different match from today,” said Murray after his win over Andreas Seppi. “Ivo will be coming to the net a lot. Returns are going to have to be on.”

The Williams sisters, who meet each other in the fourth round, Murray and finally Federer are the Centre Court line-up for Monday.

Maria Sharapova kicks off No 1 Court against the virtually unknown Kazak player Zarina Diras, with French Open champion Stan Wawrinka on afterwards against Belgium’s unheralded David Goffin. Novak Djokovic holds the evening slot against South Africa’s Kevin Anderson.

Sister act

Few would pick names outside those two courts to be involved come next weekend’s finals, with the Williams sisters facing off for the first time in a Grand Slam match since 2009. It used to be a regular happening deep into Grand Slams.

Between the US Open in 2001 and Wimbledon in 2003, Serena and Venus Williams participated in six family Grand Slam finals. The only previous major title match between sisters came when Maud Watson beat her younger sibling, Lillian, in the first Wimbledon women’s final in 1884.

This will be their 26th meeting on tour with the younger sibling, Serena leading in wins 14-11. It is their 13th match at a major, where Serena also leads 7-5 and their sixth at Wimbledon with Serena 3-2 ahead.

Serena has been the form player and, after escaping a shock exit to Heather Watson, extended her Grand Slam winning streak to 24 matches. She is aiming for a fourth consecutive major title and a self-styled “Serena Slam,” with Wimbledon the third leg of that in this calendar year.

Venus is now 35 and dealing with an energy-sapping autoimmune disease. She is not in the same shape as when she won her fifth and last title on Centre Court in 2008. Serena turns 34 in September.

“I think we probably have the most respect for each other than anyone else on the tour,” said Venus after her 6-3, 6-2 win over Aleksandra Krunic.

“I think we’re both invested in each other’s uhm, we both want each other to win when we’re not playing each other. So there’s a difference. Whereas other players, I’m not watching whether they win or lose.”

“I don’t think her legacy’s over yet,” added Venus, speaking of Serena.