At the end of 2000, Marat Safin was No 1 in the world. He had just won the US Open by beating Pete Sampras in straight sets and the American said that Safin represented “the tennis of the future”. He won an award as sporting newcomer of the year, he made People magazine's Most Intriguing People issue. And after that - well, the future seemed to stop.

He lost the No 1 spot for good within four months. Injury, plus a history of mental instability on court, had done for him. The door opened, but he failed to go through it. He might have been the alpha male of world tennis, but he wasn't. True, he picked up another grand-slam tournament, winning the Australian Open in 2005, but these days he is a man who missed his moment - a hero who might have been.

He has carried on playing, but, gifted - or perhaps cursed - with a complex and thoughtful nature, he has failed to do justice even to the shadow person he has become: ranked No 75, aged 28. This year he has won successive matches only twice, but he managed it for the third time yesterday and put out the No 3 seed as he did so. The future was back, if only for a day.

Novak Djokovic is probably the player of the year so far. He won the Australian Open, his first grand-slam title, he reached the semi-finals of the French Open and all year he has looked to be the one to break the duopoly of Roger Federer and Rafael Nadal. With Federer struggling, at least before he came here, and Nadal vulnerable on grass, this could have been his year. It isn't now.

Djokovic's playing style is rather slavishly based on Tigger. But yesterday it was Tigger unbounced. The Serb looked less than himself from the start and Safin took him out in straight sets, winning 6-4, 7-6, 6-2. At the start of every new game you expected Djokovic to find his range and blast Safin away. Failing that, you expected Safin to implode. Neither of these equally likely events took place.

Safin nailed the match the way he - sometimes - nails his ground strokes. “I took advantage that he was under a lot of pressure because he's fighting for No 1,” the Russian said. Perhaps it was as simple as that. Djokovic's serve fell apart early, mended, fell apart again. It's a difficult transition to go from being a player for whom we have high hopes and to start being a player for whom we have high expectations and yesterday Djokovic failed to make it.

For us Brits, Djokovic's most important function has been as a stick for beating Andy Murray. They are the same age, they were more or less neck and neck in the race for the glittering prizes and suddenly last summer Djokovic surged ahead and did some achieving, while Murray, injury-struck, remains merely promising. Djokovic, though, played a callow match yesterday, while Safin kept it together admirably.

The killer statistic for Safin is that in 1999 he broke 48 rackets. He gets down on himself and gives himself a terrible time and he has rowed with a lot of umpires as well. But yesterday he played solid. That's how Djokovic put it and that's how Safin himself put it.

Solid is the word: Safin is 6ft 4in and built like a linebacker. He is one of those very big, unexpectedly neurotic men, hagridden by his own sense of failure. “I didn't play great for a long time,” he said. “I don't remember how it feels.” Irony, gallows humour, bitterness: this is not a man in love with his sport or with himself. So when asked about Wimbledon he made some jokes about strawberries (“too expensive . . . not enough for dessert”) and thanked the All England Club for slowing down the courts. He had no idea who his opponent in the third round would be because he didn't expect to have one. (It is Andreas Seppi, an Italian clay-courter.)

He was booked on the 8.30 plane to Moscow last night. Now he is officially a Dangerous Floater and everybody is wondering if he really has one more big tournament left in him. “Still I'm going to the gym and still doing my things,” he said. “I think it's time for results to come. Of course it's tough to push yourself day after day when you are losing and you are losing and you are losing, get back on court, get back in the gym and do your routine.”

It is a wonderful result for Safin, a specific against despair. It is also a pretty good result for Federer, who was seeded to meet Djokovic in the semi-finals; Djokovic beat Federer in straight sets at the same stage of the Australian Open. Now the draw opens up invitingly. Is this yet another example of Federer's traditional Wimbledon luck?

Meanwhile, Djokovic is the one flying home, wondering why his serve fell apart and the unforced errors came crowding in, why it was he who played as if the court was a foot too short with a net six inches too high.

It looked to me like Centre Courtitis, for this is always the place that separates the champions from the pretenders. And Safin marches on, still with a full complement of rackets and for once on comparatively good terms with himself. “It's the third round,” he said. “Still playing great tennis.”