Murray is aiming to be the first British man to win a Grand Slam in 74 years [GALLO/GETTY]
Rafael Nadal limped out of the Australian Open, his title defence shattered by a recurring knee problem and a devastating display by Andy Murray.

Nadal quit when trailing Murray 6-3 7-6 3-0 but the match was as good as over with the Scotsman deservedly on his way to the semi-finals for the first time.

"When the big moments came in the match, I thought I dictated what happened on the court," Murray said.

"Obviously, I didn't know when he hurt his knee...but from my side, I played really well and deserved to be up when the match was stopped."

It has been 74 years since a British man won a Grand Slam title but the wait could soon be over if Murray can maintain his brilliant form for two more matches.

The 22-year-old has not dropped a set in Melbourne and will next face Croatia's Marin Cilic, who wore down seventh seed Andy Roddick 7-6 6-3 3-6 2-6 6-3 but is nearing exhaustion after spending more than 18 hours on court to get this far.

Justine Henin's dream of winning the women's championship also edged closer to reality as did that of Zheng Jie, the first Chinese to make the semis in Australia.

Henin booked her place in the last four with a 7-6 7-5 win over Russia's Nadia Petrova to set up a showdown with Zheng, who defeated Russia's Maria Kirilenko 6-1 6-3.

Nadal's exit was another sorry chapter for the Spanish second seed whose brilliant career has been blighted by knee injuries over the past year.

There must be doubts as to whether the 23-year-old can scale the heights he did 12 months ago when he held the Australian, French and Wimbledon titles and was ranked number one in the world.

"Don't start guys with these questions right now," Nadal told a news conference on Tuesday.

"I think it is not the right moment. It is impossible for me to know after half an hour."

Source: Reuters