The bruising match of almost four hours saw both men in need of treatment from doctors for assorted ailments, but the difference between the two appeared to come down to mental toughnessÃ¢â‚¬â€perhaps simply confidenceÃ¢â‚¬â€as MurrayÃ¢â‚¬â„¢s early success in a first-set tiebreak was whittled away by the Swiss.
The two men last met at Wimbledon in 2009, famous for being the first full match to be played under the Centre Court roof. That one went all the way to five sets, but since then, WawrinkaÃ¢â‚¬â„¢s ranking has slipped from the top dozen in the world as his results have weakened.
This summer, Wawrinka took on his first new coach since his junior years, the celebrated Peter Lundgren, who has coached Roger Federer and Marat Safin in the past. The trimmer, fitter, and more aggressive Wawrinka may thank Lungren for his early impact. More likely, it was the determination to make such a major change at this stage of his career that impelled WawrinkaÃ¢â‚¬â„¢s improved performance.
Murray, of course, also dismissed his coach, Miles Maclagan, this summer and postponed the appointment of a replacement. The move seemed, just a few weeks ago, to be a good one. Murray looked confident and began playing aggressive and imaginative tennis on his way to the Toronto Masters title. And that confident tennis seemed to have been carried into New York, with easy wins in his first two rounds.
What went wrong with Murray last nightÃ¢â‚¬â€other than Wawrinka turning up the pressure with some magnificent attacking tactics that had Murray retrieving drop shots, scampering to collect lobs, and reaching for one of the finest backhands in the gameÃ¢â‚¬â€is hard to say. He struggled to find reasons himself in his press conference.
His body language recalled his unexpected defeat in round four last year to Marin Cilic: hangdog, baffled, and beaten. If the impact of his defeat by Roger Federer in this yearÃ¢â‚¬â„¢s Australian final is anything to go by, he will take a long time to get over this one.
But there is always a silver lining, and this one appears to have shed its light on Rafael Nadal, surely the main beneficiary of MurrayÃ¢â‚¬â„¢s exit.
When the draw was made, the Nadal half looked decidedly challenging. Nadal was not looking in top form as he worked through the North American Masters, and he faced not only the dangerous outsiders David Nalbandian and Ernests Gulbis in his quarter but also one of the two form players of the moment, Murray or Tomas Berdych. Both men have the big, heavy games that probe Nadal. Both have fallen by the wayside.
Berdych, who picked up a thigh injury in Cincinnati, was a shock exit in the first round. Now Murray has cleared the decks for NadalÃ¢â‚¬â„¢s progress.
Things, in fact, could not be panning out better for Nadal. Gulbis, too, went out in the first found. Nalbandian ran into a Fernando Verdasco who seems to have to found his best form of the year. Last weekÃ¢â‚¬â„¢s New Haven champion, Sergiy Stakhovsky, retired in his third round match with a toe infection, and Michael Llodra also retired last night with illness.
And it should be said, too, that Nadal is playing himself into superb form. He is moving well, playing aggressively, serving better than he has ever doneÃ¢â‚¬â€routinely at 130mph plusÃ¢â‚¬â€and looking confident, even by Nadal standards. With the way cleared of all the real dangers in the drawÃ¢â‚¬â€Verdasco, the highest seed, has lost all 10 of their encountersÃ¢â‚¬â€Nadal must become favourite for the title.
Another reason to make this bold prediction is the state of the bottom half of the draw. Roger Federer has been in cruise control, not yet dropping a set. But his biggest challenges remain. He can expect to face first the world No5 in the quarters and then No3 in the semis.
Robin Soderling had a shock in his first round here, pulling out a five-set win over a qualifier, but he had arrived in New York with very little match practice. Now, he is warming up nicely.
He reached his second Roland Garros final this year, and the Wimbledon quarter-finals. New York suits his game the bestÃ¢â‚¬â€he gave Federer a good run for his money in last yearÃ¢â‚¬â„¢s quarter-final. And in his way is the veteran Albert Montanes who has never so much as reached a final that wasnÃ¢â‚¬â„¢t on clay.
Novak Djokovic is likely to await Federer in the semis if he puts away the vastly improved Mardy Fish in the fourth found and either of the charismatic Frenchmen, Gael Monfils or Richard Gasquet, in the quarters.
Djokovic likes the hard courts, and is working his way smoothly into form following some good warm-ups in Toronto and Cincinnati. He may have stumbled in the first round here, but since then he has been getting sharper, the wins have been coming easier, and his confidence seems to be growing with his results. If his schedule keeps to the cooler evenings, he is one of the most formidable opponents in the draw.
So it is an ill wind that blows nobody any good. Murray may be down and out, but his loss could just be the final piece in the jigsaw of NadalÃ¢â‚¬â„¢s campaign for his first US Open title.
MORE: The latest football news
MORE: The latest tennis news