It was hard to know which was the more surprising. That Andy Murray recovered from a set down to beat Carlos Alcaraz, a lavishly talented Spaniard who – at 18 – is barely more than half his own age. Or that he introduced a new stroke – the underarm serve – at this late stage of his career.

Murray’s multi-faceted game features all kinds of tricky variations, lobs and dinks, but we had never seen him deploy this particular sleight of hand before. He brought the shot out at game point, early in the second set, when Alcaraz was standing so deep that he was in danger of getting the bends.

Happily, Murray nailed his execution – because it always feels anti-climactic when a player deploys this cheeky, provocative shot as a surprise tactic, and then fails to find the service box. 

The ball landed nice and short over the net and had bounced twice by the time it left the court. Alcaraz was so badly stranded that he didn’t even bother to take a step forward. Instead, both men walked straight off the court and back to their chairs.

“I’ve never done it on the tour before,” said Murray afterwards, “[but] the courts are so slow. I served [only] three aces in a long match, one of them being the underarm serve.

“I thought ‘If he’s going to stand that far back and I’m getting no love from the court and the conditions, why not try it and see if I can bring him forward a little bit?’ I wasn’t expecting to get an ace out of it [but] he was so far back, he didn’t react. When guys are standing there to return serve now, it’s a smart play.”