The skies were grey but the air around the Prince of Perversity, Andy Murray, was oddly blue for much of a rain-split win in straight sets over John Isner to reach the quarter-finals of the French Open for a record sixth time.

It was Fred Perry – naturally – who held the previous British highwater mark here, way in the distant past, and Murray can make history again if he can win three more matches in a tournament decimated by injury and upsets, among them that of eighth seed Milos Raonic earlier in the day, before the rain arrived in the late afternoon.

This is the only slam final Murray has never reached. It will not be easy, but it is not beyond him. To reach the semi-finals he will have to get past Richard Gasquet – and a partisan crowd – after the Frenchman beat the No5 seed Kei Nishikori 6-4, 6-2, 4-6, 6-2.

Murray, seeded second, beat the 15th seed Isner 7-6 (11-9), 6-4, 6-2 in style inside three hours – yet anyone who walked in late on his serial rants surely would have thought he was enduring the worst afternoon of his career.

Time and again he chastised himself – and his box – for often forgiveable slips. It is his preferred method of raising his level but it seemed unnecessary in this contest. For most of the exchanges, he ruled his 6ft 10in opponent with deft use of short balls, passing shots and a solid serve, finding aces or big first serves when it mattered.

Tie break success

“It was very important to win the tie-break, could have gone either way,” Murray said courtside.

“I just guessed the right way on a short forehand. To go in on that rain delay was very important. Some times you have to guess on John’s serve, but you have to try not to let him put you under pressure. It’s obviously difficult conditions, you don’t quite know what’s going to happen.”

Isner dominated much of the first set, but Murray prevailed in the tie-break, one passing forehand on the run to save set point a candidate for shot of the weekend.

When they returned, Murray let Isner off the hook twice on his serve in the first six games. He wasted a further break but struck when it mattered to go two sets up, outfoxing the American at the net with a deft backhand chip that left the big man stranded yet again.

In the third, Isner lost the plot – and, as it happened, pretty much the whole shooting match – when he let a marginal line call against him at break point on his serve in the fourth game rattle him. Murray, for once, stayed cool and ground out the break.

Murray got a second-serve ace – his sixth against 16 – and held to 15 for 4-1. He gave Isner a look in the seventh game before regaining focus.

Isner held with the power of his serve, and Murray stepped to take the win on his own racket, but faltered a couple of times – “You’re going to mess this up,” he muttered when a first serve strayed wide at 15-30, then handed Isner break point with a sloppy backhand. He saved with an ace.

Isner hit long and Murray converted match point with another one, after two lets. It was a strangely angst-driven but convincing performance, another one for the collection.

If he plays like this in the quarter-finals, he should not have much to swear about.

Before the rain returned to Paris like an unwanted guest, Stan Wawrinka put 19 aces and 67 clean winners past Victor Troicki to send a message to the rest of the field – and Murray, potentially, in the semi-finals – that he is in the right mood to hold on to his French Open title. The Swiss beat the Serb 7-6, 6-7, 6-3, 6-2 to win in just under three hours.

Raonic upset

However, the third seed will not be playing Raonic next, as expected, but the the world No55 from Barcelona, Albert Ramos-Vinolas, who upset the Canadian 6-2, 6-4, 6-4 in just two hours and 20 minutes in the first match on Lenglen.

John McEnroe dropped a minor bombshell earlier in the week when he said he would be joining Carlos Moya and Riccardo Piatti in a crowded coaching team for Wimbledon. He was there to witness this setback. At least he will have an extra week to work with him.

Ramos-Vinolas is a 6ft 2in, 28-year-old Spanish clay-courter from central casting, who grew up under the influence of Murray’s one-time coach, Alex Corretja, and trains still alongside, among others, Garbine Muguruza in Barcelona.

After Muguruza beat the 2009 champion Svetlana Kuznetsova in straight sets to go through to the quarter-finals, she said of Ramos-Vinolas, “I see him in Barcelona training. He’s just a very quiet nice, guy.”

And he’s making a bit of noise at this tournament. Ramos-Vinolas said later, “I lost I think four times in a row first round, and this year, quarter-finals. So I’m really, really happy. Although this is not Raonic’s favourite surface, I feel quite humbled to have won against him.”

So, there is a polite Spanish left-hander in the quarters, after all – just not the one anybody had predicted. – Guardian service