Rafael Nadal did his best to shrug off his latest Grand Slam setback on Tuesday and pledged to fight on - despite the "crazy", go-for-broke tennis now played by some of his rivals.

The 14-time Grand Slam champion, just three behind all-time leader Roger Federer, bombed out in the opening round of the Australian Open to fellow Spaniard Fernando Verdasco.

In only his second first-round loss at a major tournament, Nadal, 29, fought for four hours, 41 minutes before Verdasco prevailed 7-6 (6), 4-6, 3-6, 7-6 (4), 6-2.

But Nadal was not seeking excuses as he heads home to work towards his favorite Grand Slam at Roland Garros, where he is a nine-time champion, in late May.

"The match is a tough loss for me, especially because it's not like last year when I arrived here playing bad and feeling not ready for it," Nadal said.

"This year was a completely different story. I have been playing and practising great and working so much.

"You know it's tough when you work so much and arrive at a very important event and you go out too early.

"It's tough, but at the same time, I know I did everything that I can to be ready for it. It was not my day. Let's keep going. That's the only thing.

"There is nothing more to do than keep working hard, keep practising the same way that I was doing the last four, five months."

It was one of the most disappointing Grand Slam performances for Nadal, who also lost in the first round at Wimbledon in 2013 and has not won a major title since the 2014 French Open.

Nadal has now failed to advance beyond the quarter-finals in his last six Grand Slams, as well as missing the 2014 US Open through injury.

Of his 14 Grand Slam successes, only one has come in Melbourne, in 2009.