Thursday's US Open quarter-final cannot help but bring to mind the time when Andy Murray was human. The last match he played against Stan Wawrinka at Flushing Meadows was also the last defeat he suffered in the first week of a slam. And that was three years ago. Wawrinka was the world No27 then, a strong-shouldered blond with a backhand to make grown men weep.
Yet, for all his undoubted ability, his self-belief cannot have been helped by standing in the alpine shadow of Swiss compatriot Roger Federer, then arguably the most gilded and gifted sportsman on the planet. As we return to our starting positions today, much has changed.
Yes Murray is a new man since the appointment of Ivan Lendl, and the capture of two grand slam titles. But then so is Wawrinka, who showed his class on hard courts when he made Novak Djokovic look mortal in a classic fourth-round match at January's Australian Open.
Neither Murray nor even Rafael Nadal has bullied Djokovic - who has not lost in Melbourne since 2010 - with such supreme insouciance in Rod Laver Arena, the court the world No1 loves more than any other. Admittedly, it did not last. Djokovic recovered from a 6-1, 5-2 deficit to squeak through 12-10 in the deciding set. But heartbreaking losses can often be the start of something special, as Murray himself proved after last year's Wimbledon final. "That was the match that meant so much for my confidence," said Wawrinka, who has recently regained the final position in the top 10.
"I am quite an unsure guy on the court. I always have some doubts and after that match I had the feeling that everything I was doing outside, the practice, was in the right direction. "Tennis is very much in the head. The top 20 players play amazing tennis but the changes are in here, mentally. The only thing for sure now I think I'm completely mature to play tennis and I hope the next four years I will be at the top of my career.
"I am sure Andy will not be 100 per cent confident because he knows how well I can play and he has had some difficult matches against me." True enough. It feels strange to say it, but given a choice between the two leading Swiss players, one suspects that Murray would have preferred Federer, a man he has beaten in three of their last four meetings. While he may hold an 8-5 head-to-head lead over Wawrinka, that is likely to count for little as both men have reinvented themselves so dramatically.
On the evidence of the first four rounds, Murray has yet to rediscover the elan that made him champion here 12 months ago. But then, he made a meal of two of his early matches last year too, notably while losing more points than he won in a four-setter against Feliciano Lopez. Asked yesterday about the importance of momentum, Murray shrugged. "I always say that in tennis, it doesn't really matter what happened two days ago. You turn up on the day of the next match and you might feel awful. I saw some of Stan's match yesterday, it looked like he played extremely well."
Wawrinka knocked out fifth seed Tomas Berdych in four sets. "But the matches will get tougher now." This year, Murray hit a few more potholes on his way to a 6-7, 6-1, 6-4, 6-4 fourth-round victory against world No67 Denis Istomin. Coming after the Arthur Ashe Stadium crowd had just witnessed four successive 'bagel' sets from the respective world No1s, Novak Djokovic and Serena Williams, it was at least a contest with some small element of suspense.
Still, such is Murray's extraordinary consistency at grand slam events that no one ever seriously imagined that he might lose. He has now won his last 44 matches on the way to major quarter-finals, dating back all the way to that peculiar night in Louis Armstrong Stadium when he seemed to suffer a power failure against a far more energised Wawrinka.
"I struggled on that court, so I don't have particularly good memories from that match and I did go away from it a bit down," Murray recalled yesterday. But he did point out that he had also thumped Wawrinka in under two hours in Arthur Ashe Stadium two years earlier. That was the first time he had played in the night session here, in the most electric atmosphere available on Planet Tennis, and he was so excited that he was running on pure adrenalin. Perhaps we get a little blase about the feats achieved by tennis's leading men.
Federer, it might be pointed out, made 33 straight major semi-finals at the grand slams, while Djokovic stands on 13 and counting. Murray might not quite be in their company, but 11 successive quarter-finals is still a phenomenal effort. He has survived rain delays, back spasms, twisted ankles, inspired opponents, roof closures, Wimbledon curfews and the constant, massive pressure of expectation. Yet this is the life of a tennis player. There is always another match to win.