Brazilian fans love the underdog and any sign of annoyance or displeasure from Andy Murray provokes boos of disapproval from the local crowd, who are half rooting for Kei Nishikori, mainly because they want to see a third set of tennis.

This was a match which exemplified why tennis, although a relatively new Olympic sport, had none of the difficulties currently experienced by golf as it settled in. Novak Djokovic’s tearful exit confirmed that playing for your country is different. And on another baking-hot winter’s day in Rio, Andy Murray played his way to the opportunity of becoming the first ever tennis player to defend his gold medal, it wasn’t hard to see what it meant to him.

The pale Scot was at his inimitable best here, at times raging against everything from the machine to the photographers (their lenses were too long and too close to where he was serving), against a few line calls and against himself.

If Roger Federer is tennis’s version of effortlessness, then Murray operates on the other end of the scale, always demanding more work out of himself and only fully winning the crowds emotion with his penultimate shot when he engaged Nishikori in a fabulously long, intense rally which he settled by slinging his racket at the ball even as he fell onto his butt. It was a bit of a circus shot but the exchanges for the prior 30 seconds were brilliant.

“I think I hit three or four great backhands and then he managed to turn the point around,” Murray said when he emerged from the venue in Olympic Park.

“He had a sort of volley which he mishit slightly and I came up with a bit of a lucky shot up the line. I didn’t even see it bounce so I didn’t know if it was in or not. And thankfully it was good. I was just pumped because at that moment, if he turns that point around and breaks it’s a totally different match. It was a huge point. The shot itself was a bit lucky – you don’t practice shots like that. It’s the work you do off the court for those long points that you have to prepare for.”

It takes Murray almost as long to do the obligatory television and media interviews as it did to win the match. Fifteen different television crews are waiting to quiz the Scotsman, mostly about what it would mean to win a second gold medal.

“That would obviously be nice” he said in his steadfastly sound bite-averse style.

“The goal is to win a gold medal. I’m not really thinking about any of the stuff that goes with that just now. It is obviously a difficult thing to do; hence nobody has ever done it before.”

In a way, all the questions were superfluous. You only had to watch Murray and his brother Jamie to engage the Brazilian doubles team last weekend in a hugely entertaining game to see how much this Olympics business means to him. He was crushed when the pair crashed out. It was the same on Centre Court.

He cruised to the first set 6-1 and after breaking Nishikora in the game five, he produced the heavy artillery, drilling first serves of 172 kph, 203 kph (an ace), 176 and 177 to deliver a love game and consolidate his advantage at 4-2.

Nishikori had the potential to win points of Murray every time he lured him to the net – a beautifully disguised lob early in the first set was one of the match highlights. But Murray has become adept at forcing matches to suit his own terms. After winning that crucial point against Nishikora, Murray raised both arms aloft. When he served out the match, he permitted himself one of his extra-specially intense howls at the moon.

Nobody can claim that Murray isn’t an exceptionally proud Brit. He is arguably unlucky to have reached his athletic peak in an era when tennis is crowded with all-time greats but through pure self-determination and intelligence fuelled by a fast temper, he is enjoying a period of dominance, with Sunday’s gold medal match following his triumph at Wimbledon in July. At 29, he may be having the season of his life.

“Well the last four months definitely have been. My job is to keep that going now and keep up that consistency. I’ve not had my best tennis this week but I’ve found a way to win and, you know, often in matches like the one yesterday where if you get through you start to find form and get better as the tournament goes on. I’ve had that a few times: at Queen’s the same thing happened and Wimbledon against Tsonga I have that match that could have gone either way in the fifth set.”

He will play Argentina’s Martin Del Potro in Sunday’s final after he came through an epic three-setter against Rafa Nadal. If he retains gold, expect tears.