The mayhem on the court spreads to Team Murray and there is an eruption of roars, claps above the head, fist pumps. Ivan Lendl is not infected. He rubs his face languidly with his hands, taking care not to dislodge his sunglasses.
He prowls the court with his racket swinging by his side as the cameras whirr and click and Murray batters a ball towards a hitting partner. There is the odd word, the occasional grin and a word of praise or encouragement. The coach is relaxed at his work.
It is difficult to read Lendl but Murray is finding his stories both beneficial and edifying. The lazy stereotype labels the 52-year-old Czech as a father figure to the 25-year-old Scot. The truth is some way from that but Lendl, an eight-time major champion, has been giving his protege some bedtime tales.
The partnership began just before the New Year and Lendl has become an auspicious first foot for Team Murray. The Scot reached the Australian Open final and now stands just one step from his first Wimbledon final.
Murray has had to adapt to Lendl's ways. "We speak about different things than I was used to because he is a different coach, different person. I now talk tactics the night before a match," said the world No.4 who faces Jo-Wilfried Tsonga of France today.
"He's very exact. he doesn't miss anything. He gives you a lot of information on players so I have started to talk the night before matches, so I can process it, think about it the night beforehand. That's really been the big difference. He is making sure I am focusing on the match the night before, so I can sleep on it and make sure I am prepared, rather than not thinking about the match at all and maybe starting off a little bit slow."
Lendl also speaks to Murray about half an hour before a match to give final instructions and information.
It is impossible to gauge the precise difference that Lendl has effected on Murray but the Scot has negotiated different styles of player at Wimbledon with some conviction.
The marvellous victory over David Ferrer was a combination of good strategy, committed execution and strength of character. Murray does not divulge much of the inner workings of his team but does point to one significant change made by Lendl. Murray's serve was highly influential in a tight fourth set but the Scot said: "Ironically, I hit a lot fewer serves than I used to in practice. Ivan is more of the opinion that you need to rest your shoulder and make sure it is loose, not tired, when you go out on to the court and into big tournaments because over the course of two weeks you hit thousands of serves.
"I have hit a lot fewer serves since I started working with him. That maybe is a reason why I am serving well deeper into the tournament. He has worked a lot on my second serve too since the start of the year and that is something that has been good. Against, Ferrer it was not always about the pace of the serve. I was getting a lot of kick on it and making him hit a lot of very high returns that he struggled a lot with."
The serve will be crucial against Tsonga today. In many ways this semi-final carries the same back story as Murray's meeting with Andy Roddick in 2009. The Scot was heavily favoured to beat a player who relied heavily on power but he was beaten and that defeat rankles more than any other at the highest level.
"I remember it being a close match. I got into the match pretty well. Had chances. He served incredibly well and I didn't take my chances. I wasn't incredibly nervous going into the match. I was feeling fairly comfortable," he said.
Then he added: "That has maybe been my toughest loss so far in a slam. I definitely will have learned from it."
Tsonga may regard Murray as a lucky omen. He defeated the Scot at the Australian Open of 2008 and went on to the final. It is his only victory in six matches against the world No.4.
He will rely on a heavy serve, quick movement and leave the rest to fate. Murray must make his serve impregnable and trust in his returning skills to force a break, perhaps even in a tie-breaker.
Murray was relaxed in the interview, accepting he was in "a good place".
"This year has been one of my toughest draws so I have had to play some of my best tennis to get here," he said of a run through Nikolay Davydenko, Ivo Karlovic, Marcos Baghdatis, Marin Cilic and Ferrer.
"At the Australian Open this year I did not have to play so well because the guys I played against were shattered, but this time it has not been like that. It has been very tough. There have been tough matches against different types of players as well. My game should be in a good place going into the semis."
Murray will walk out on to the Centre Court today accompanied by the expectations of a nation. He insists he is not burdened by this.
The Scot regularly visits Wimbledon to sit on Centre Court and reflect on a seven-year career at the All England Club that has been turbulent, at times brilliant, at other times deeply disappointing.
He has made many walks by the Fred Perry statue outside the greatest court in tennis. This celebrates the last British player to win the gentlemen's singles at Wimbledon, 76 years ago.
Does he ever glance at the ghost that haunts British tennis?
"No, not really," he said. "When I think about Wimbledon and how long it has been since a British winner it is obviously surprising, a bit shocking too. But I am very selfish when I think about Wimbledon.
"I really try to make sure that I want to do it for myself. When I sit out there on the court, I am thinking about the history and the matches that have been played there by myself so that I understand how important it is and so I know that when I come here I do not want to waste the chance by playing a stupid match or not acting right or not preparing properly. I do all of that to try to benefit myself.
"I haven't looked at the statue or thought too much of Fred Perry. If I did, it might not be beneficial, especially at this stage of the tournament."
The Scot is doing it for himself this afternoon. Lendl, and the mass of Murray support, can only look on in hope.