Andy Murray insisted he is “not a robot” as he defended his on-court behaviour after beating Italy’s Matteo Berrettini in the first round of the Miami Open.

Murray recovered from losing the first set for a 4-6, 6-3, 6-4 victory in a match in which Berrettini needed medical treatment after feeling faint in the extreme heat. The former world No1 was seen faux laughing at himself as he battled with his emotions on court.

And after setting up a second-round meeting with No29 seed Tomas Martin Etcheverry, he said: “If I’m laughing, it’s not okay. If I’m shouting, it’s not okay. If I’m flat, like I was in Australia, that’s not okay.

“It’s very hard for me to get the balance right. I’m very different on the tennis court. I’m not a robot. I’m a bit odd, a bit strange, but I play better when I am like that.”

Murray has struggled with his form this season and recently admitted he did not see himself playing much past this summer.

Wimbledon and then the Olympics look like being potential swansongs for the three-time Grand Slam champion, although he insists he still has no idea when he might officially call time.

This win, in only his second tournament since last year’s US Open following injury, was, arguably, his most impressive of the season.

“I think in terms of the way I played and the important moments, I did a good job,” he said.

“I stayed tough and played some good points. I moved well and dictated a lot of the match, which isn’t easy against him. Once I got the balance right, I dictated a lot of points. I played a smart match when I needed to.”