Stanislas Wawrinka causes Rafael Nadal to feel the pain of defeat at Australian Open

All the talk before Sunday's Australian Open final suggested that Stanislas Wawrinka might need a thunderbolt to strike down his opponent, world No1 Rafael Nadal, in order to lift the title.

Perhaps Wawrinka's camp performed some dark rite of invocation, because Nadal did find himself crippled by a back spasm in what must rank as the weirdest grand slam final in living memory. Yet this is not to say that Wawrinka - the first-time finalist who eventually came through 6-3, 6-2, 3-6, 6-3 - was an unworthy winner of the year's opening major. Yes, he had a clear physical advantage. But he also had to deal with the brain-scrambling effects of playing a hobbled opponent, a notoriously difficult challenge for any tennis player. On the biggest day of his professional life, it was no small feat to keep his emotions in check.

The "big four" have exerted such a stranglehold over the past decade - winning 34 of the previous 35 majors between them - that you always felt it would take something exceptional to break the sequence. And this match was certainly that. It started with Wawrinka's own personal version of the 1812 Overture. His groundstrokes sounded like cannon-fire as he bullied Nadal throughout a spectacular first set. Was Nadal already feeling off colour? He was unusually passive, for sure, and his forehand lacked its usual fizz.

Spectators exchanged puzzled looks when he held three break points to level at 5-5, yet failed to land a single return in court for the rest of that game. It was after Wawrinka had sealed the set with an ace, after just 37 minutes' play, that things turned increasingly surreal. First Nadal pulled up abruptly after dumping a regulation forehand in the net. He bent double, put a hand to his back, and disappeared off the court with the trainer while Wawrinka furiously demanded to know what the problem was. When Nadal returned after a six-minute delay, he was roundly booed by the crowd - an experience he can never have endured before on Rod Laver Arena.

Yet there was immediate evidence that he was not malingering as his first-serve speed dropped to around 80mph. He could barely move along the baseline and had to rely on swinging hard at anything that came within his reach.

"The back, since the beginning I felt a little bit, from the warm-up," said a crestfallen Nadal after the match. "End of the first set, I start to feel worse. Then at the beginning of the second was the key moment that I felt, during a serve in a bad movement, is very stiff, very bad. The physio tried to relax a little bit the back. When that happen during a match is almost impossible. "Last thing that I wanted to do was retirement. No, I hate to do that, especially in a final. During the whole year you are working for a moment like this, and arrives the moment and you feel that you are not able to play at your best. I tried to finish the match as good as I could for the crowd, for the opponent, for me. But was impossible to win this way. Opponent is too good." After the medical time-out, play resumed in a hesitant sort of way, in front of a crowd that did not know quite how to react.

Wawrinka finished the second set off quickly, but then seemed to be gripped by the prevailing mood of bewilderment. He lost the timing on his groundstrokes and allowed Nadal - who was only functioning at around 20 or 30 per cent at this stage - to pull a set back. "It was a really difficult situation," said Wawrinka's coach, Magnus Norman, last night.

"I thought Stan was a little bit soft in the third set. Obviously it's really difficult when you play someone and you feel that he is suffering. You get tentative, and he was pushing his shots a little bit. "You know that Rafa will not give up, if you give him the chance to come back," Norman added. "I didn't like the idea of the match going to the fifth set. But then in the fourth Stan came back again and started to play his game. His body language was more positive again. I was obviously really happy with the way he handled the end of the match." If Wawrinka had continued to waver, this could have ended badly for him.

The commentators were starting to invoke the spectre of Guillermo Coria, the Argentine who threw away a two-set lead in the 2004 French Open final But Wawrinka steeled himself and managed to rediscover the booming forehand that had dominated the first set. Nadal's serve speed and movement were actually picking up now, presumably as anti-inflammatory medicine kicked in, but he could not sustain his resistance once the freebies stopped coming his way. It was fitting that a Wawrinka forehand down the line - the most potent shot throughout this match - should have concluded matters after 2hr 21min of unpredictable drama.

At the post-match ceremony, an emotional Nadal received the sympathy of a repentant crowd. He looked close to tears, as he had been during the various changeovers when the physio rubbed his back. But he is a classy character, in victory or defeat, and he showed it in his reaction. "Is the moment to congratulate Stan," said Nadal.

"He's playing unbelievable. He really deserve to win that title." Given that Wawrinka had just become the first man to beat both Nadal and Novak Djokovic in the same grand slam, it is hard to argue otherwise.