WHEN you strike the ball as ferociously as Stan Wawrinka does you must go through a fair few racquets. But rarely does the Swiss feel demoralised enough to destroy one as clinically and comprehensively as he did yesterday. Trailing by a set and a double break to an imperious Andy Murray, he placed his on the ground, stuck one foot on it, and pulled up either end until it snapped.

Regardless of a warning for racquet abuse - the kind of felony which even Jonny Cochran or Donald Findlay wouldn't be able to get him off with - the World No3 then folded it neatly and handed it to a lucky young fan in the o2 crowd. The recipient of the gift might consider himself to have been luckier still if he had been given one that was still in a recognisable enough form to be able to take down the local tennis courts this morning for a hit.

Anyway, the meticulous destruction of the racquet was emblematic of an encounter in which the new World No 1 seemed to unpick the unravelling US Open champion string by string. Wawrinka on his day is a fearsome opponent, such a clean ball striker of either wing that he can be well nigh unplayable.

The Swiss has won one Grand Slam in each of the last three years, enough of course to equal Murray's haul in the majors. He has beaten the reigning World No 1 three times in this event and even appeared to be playing his way into form with a straight sets win on Wednesday night against Marin Cilic. In fact, all permutations were open in Group John McEnroe as the day began, with the Scot knowing that straight sets wins for both Wawrinka and Nishikori could leave him on the outside looking in on semi-final day, having to hand back his hard-earned No 1 ranking to Novak Djokovic after a fortnight.

This, though, is the world's best tennis player we are talking about. A man who has never been more programmed to win tennis matches. The Scot is the sport's main man because quite simply these days he has the measure of most of his opponents.

With his big brother to catch up on, after Jamie and Bruno Soares were confirmed as the top doubles team of 2016, the younger Murray sibling read the script here and stuck to it. He didn't sink to the depths of despair when Wawrinka came out firing, merely soaked up the Swiss man's power and waited for the storm to subside. While the Scot knew taking a single set would be sufficient to book his semi-final place, by the end - with Wawrinka firing 27 unforced errors to Murray's 13 - there was only one outcome, the 6-4, 6-2 margin of victory emphasising the gap between the best and third best players on the planet was a yawning chasm.

This was the Scot's 22nd win a row, tied for his longest-ever winning run. That other spell, also compiled this season, included his Queen's Club, Wimbledon and Olympic titles and if he keeps playing like this who knows when this sequence of successive Scottish silverware will stop. In the short-term, it ensured that he progressed with a perfect 3-0 record to a semi-final against Milos Raonic this afternoon, keeping him on course for a shoot-out for the soul of the sport on Sunday against Djokovic.

Swiss flags are de rigeur at this event, usually flying for Roger Federer, and there were times in that opening spell when Wawrinka was just too good. But backing yourself to cream howitzers over the high part of the net only works if you are actually making them. A fist pump from Murray after a loose backhand from the Swiss set up the match's first break point, the crowd getting into it to the extent that the umpire felt moved to ask "especially the ladies and gentlemen in the 'hospitality' boxes" to keep the noise down during points. Perhaps, as John Lennon might say, they were rattling "their jewellery" too loud. In any case, Murray was seeing Wawrinka's serve clearly and a unerring return to an inch of the base line and an approach which skipped off the net was enough for him to break for 4-3. While Wawrinka dug deep to save three set points and make the Scot serve for the opening set Murray made light work of that.

With his place in the semi-finals secure, Murray could relax and swing more freely while Wawrinka's game became more error prone. Some more mis-hits came along as the Scot broke the Swiss serve at the start of the second set, and that promptly became a double break despite Murray hitting the large neon scoreboard which hangs above the centre of the court. When one last top edge from the Swiss flew long Andy Murray had win No 22 and David Bowie came over the Tannoy, singing something about being a hero just for one day. Forget that: the World No 1, on the other hand, is an everyday hero who shows no signs of settling for second best any time soon.