That fourth set was mind-boggling. There were seven breaks of serve in the 12 games and one extraordinary statement point from Murray which saw both men cover all 2,800 square feet before he finally came up with a winning pass, leaving Del Potro bent double over the net. You could tell, at that moment, that he was fully locked onto his target.

After the match had ended via a netted backhand from Del Potro – probably the most common conclusion to these 269 breathless rallies – both men met at the net in a damp and emotional embrace. Murray then took to his chair and heaved huge sobs into his towel, while del Potro did not bother to hide his tears, his face by now turning puce with exhaustion and emotion.

Even amid the all-round mastery of Team GB, Murray stands out from the Stella McCartney-clad crowd. This is a man who has already peaked at least three times in 2016, reaching the finals of each of the grand slams and lifting the Wimbledon crown. But he was desperate to deliver for the team, particularly after his central role at the opening ceremony.

“Getting to carry the flag was an amazing experience,” he reiterated last night. “It's a great honour to get the opportunity to do that. I found that quite emotional. After the day I did it, I sort of had to regroup and get my mind on the matches. A match like that [tonight] as well, the build-up the last 10 days or so, it's been very emotional. I'm just very happy to have got over the line. I'm so tired.”

Would he be showing the film to his daughter Sophia – who is still only six months old – in the future? He smiled. “I don't know to be honest. When she's old enough I'll try to tell what I've done in my job, if you can call it that. I'm sure there'll be some videos somewhere so I can show her some of the matches – if she's interested. Maybe she won't be. A lot of the tennis players that I've spoken to have children, and they're more interested in the other players than in their fathers.”