Cruel from Murray, slicing low again and again, forcing the big man to bend low and dig dig dig. Murray now creating space for a flat forehand down the line, but his second serve is a little powderpuff, and that's ammunition to Anderson's fast, flat forehand. Deuce, ace out wide, sparks snuffed out.

John McEnroe
Three-time Wimbledon singles champion on BBC TV

"Murray is going to be successful unless Anderson comes up with a Plan B, he has made a good start once again."

Trouble for Anderson, pushed back by successive Murray forehands, so far at least unable to come up with any answers when the point extends. Chance for the first break of the day for Murray, and when the splay-legged Anderson sticks a flustered backhand long, the Briton has some valuable first-set daylight.

Image source, Getty Images

1976 and 1972 Wimbledon runner-up Ilie Nastase has dressed up for his day in the Royal Box. From the look of those decorations he's been dabbling in military life, knowing him in the Barmy Army. Nerve-cooling hold from Murray, the big South African unable to cope with his movement.

Image source, Reuters

Holy moly! A break of serve out on court three and Feliciano Lopez deserves his place in the fourth round for that alone. The Spanish 19th seed does have to serve out to claim his prize though.

He does - to love as well - and will play Stan Wawrinka, who beat Denis Istomin in straight sets earlier, in the last 16.

A tantalising match-up, this one: the home hero, reigning champion, against a 6ft 8ins serving trebuchet whose father built a wall in their garden at home so his son could practise. When Anderson lands his first serve the point is short. When he doesn't, or when Murray gets a piece of it, the point extends and Murray's grip tightens. Hold to 30, enervating start.

Image source, AP

Marin Cilic has Jeremy Chardy just where he wants him, two sets and a break down.

The Croat is three solid service holds away from a place in the quarter-finals.

Afternoon all - in good shape for this fourth round ding-dong? No matter how robust you're feeling, you won't be looking as perky as Sir Cliff Richard's hair, as Britain's Duane Eddy (TM) sits in the Royal Box a few seats away from Sir Alex Ferguson. It's such an unbroken shade of dark brown it's like he's had it creosoted.

Image source, AFP

It's almost time for the next chapter in Andy Murray's Wimbledon story so I'll leave you in the capable hands of Tom Fordyce.

Sam Sheringham
BBC Sport at Wimbledon

"While Andy Murray gets down to business on Centre, I've just pitched up at Court One to watch Grigor Dimitrov and Leonardo Mayer battle it out to be his likely quarter-final opponent.

"Bulgaria's Dimotrov was once dubbed "baby Federer" and it only took a single sumptuous swing of his one-handed backhand to realise why. Mayer, at the net, barely had to time to flinch as the ball fizzed past him for a winner down the line."

John McEnroe
Three-time Wimbledon singles champion on BBC TV

"These guys have practised together, they are familiar with each other's game and Murray knows what he can do on his return of serve.

"I think Andy finally came right from his injury around Rome, he got to the semis at the French and then thought 'Ok, now I know I can do it.'"

Centre Court erupts as Murray strides purposefully into the venue, with the roof now completely open. He spends little time at the chair, instead heading straight to the net for the formalities before getting on with the warm up.

Here's how the stats compare between defending champion Andy Murray and 20th seed Kevin Anderson.

Ross Hutchins
British doubles player on BBC TV

Image source, AFP

"Kevin Anderson has more than just a big serve, he has beaten some big-time players, and Andy Murray. He has a lot of variety to his serve, a big forehand as well and he is at his best at Wimbledon, but I think Andy will have too much for him today."

Today, we're asking which men's player has the best serve, both past and present. Choose from the six on the right-hand side of the page as well as sending your thoughts over via Twitter using the #bbctennis hashtag, text on 81111 (UK mobiles) or the BBC Sport Facebook page.

Tim Henman
Former British number one on BBC TV

On the roof being pulled back on Centre Court: "It takes time to put the coins in the meter! It is an outdoor tournament, so you have to make the effort to play the games outdoors. But the last thing you want is opening the roof to then shut it again and waste more time, and we have wasted enough time this week with the weather."

The roof is being opened which means there's a slight delay in Andy Murray and Kevin Anderson walking on court.

Image source, Reuters

After Saturday's rain delays, Stan Wawrinka will have to win five matches in seven days over the second week if he is to win Wimbledon this year. The Swiss admitted he was "disappointed" by the tournament organisers failure to re-jig the schedule to get his meeting with Denis Istomin played before Sunday's rest-day.

"If you look for this week, me, Feliciano Lopez or John Isner have to play three matches in three days. It's terrible for the body," he said.

"They just say what's going to be the schedule and that's it. Even if you want to talk to them, they're not going to change anything.

"They don't listen the player. They just do what they think is good for them."

The waiting for those on the hill and in Centre Court is almost over as defending champion Andy Murray and South Africa's Kevin Anderson are the next match on.

Feliciano Lopez wins the third successive tie-break of his match against American John Isner.

Sixty-eight aces on the clock so far...