Stanislas Wawrinka shows the trophy to the Melbourne crowd.

Stanislas Wawrinka held firm in a match of high drama to defeat an injured Rafa Nadal 6-3 6-2 3-6 6-3 and win his maiden grand slam title at the Australian Open yesterday.

The eighth seed roared to a two-set lead after top seed Nadal struggled with an apparent back injury sustained early in the second set, but the Swiss was left stunned as his opponent suddenly revived in the third at Rod Laver Arena.

Though restricted in his movement, Nadal fought back into the match with a barrage of clean hitting, completely throwing the Swiss off his game who surrendered the third set in a hail of unforced errors.

Wawrinka captured a break in the fourth set, surrendered it with a terrible service game, but recovered again to earn a chance to serve for the match.

He stayed cool when it counted, serving strongly and sealing the win with an imperious forehand rocketing down the line.

A relieved Wawrinka raised his hands in the air in celebration and after shaking hands with a gloomy Nadal, went to console the Spaniard at his chair.

“First, Rafa, I’m really sorry for you, I hope your back is okay, you are a great friend and a great champion,” Wawrinka said at the trophy ceremony.

“You did a remarkable comeback last year. For me it’s the best grand slam ever. Right now I still don’t know if I’m dreaming. I guess I’ll find out in the morning.”

The 2009 champion Nadal shed tears at the trophy ceremony, overcome by the emotion of a roller-coaster match.

“First thing I want to say is, thanks to Stan, we have a great relationship and you really deserve it today, so many congratulations and all the best.

“To all the crowd, it’s been an emotional two weeks sorry to finish this way, I tried very, very hard. Last year was tough when I wasn’t able to play here... thanks for your support, see you next year.”

The triumph capped a remarkable fortnight for Wawrinka who became the first man in 21 years to beat the top two seeds at a grand slam since Sergi Bruguera pulled off the feat at the French Open in 1993.

Five days after ending second seed Novak Djokovic’s three-year reign at Melbourne Park, Wawrinka denied a distraught Nadal from becoming only the third man to have won all four majors at least twice.

Nadal had treatment on his back from a physio and whether it was painkillers or just pure grit, he showed signs of a revival in the third set.

A searing forehand winner down the line gave Nadal two break points and astonishingly, the Spaniard broke a flat-footed Wawrinka when the Swiss bunted a bloodless forehand into the net.

Still restricted in his movements, Nadal began gunning for the lines and his stand-and-deliver approach saw him march to a 5-2 lead.

With Nadal serving for the set at 5-3, Wawrinka had a chance to break back but was unable to flush the tension out and conceded the set when he smashed a forehand into the net.

As Nadal held on, Wawrinka continued to battle with his mind as he broke Nadal in the final set and then gave it straight back.

Amid the doubts, the Swiss’s serve never quite deserted him and it carried him to match point before his forehand sealed it to raise thunderous cheers from the terraces.

Mixed doubles final: Mladenovic/Nestor beat Mirza/Tecau 6-3 6-2.