Bidding for a record 21st grand slam men's singles crown, the Spanish legend will face Italian seventh seed Matteo Berrettini in the semi-finals for a place in the Australian Open decider.

Of all four grand slams, the first of the calendar year has been Nadal's least successful in terms of silverware.

But without Roger Federer and Novak Djokovic at Melbourne Park this year, Nadal now has a golden opportunity to become men's tennis's all-time majors title leader.

The three greats are locked on 20 slams each.

Djokovic was favourite to take the mantle by claiming his 10th Australian Open title, but the world No.1 was deported to Serbia before the tournament began following the drawn-out saga surrounding his visa.

At 35, Nadal is simply happy to still be contending in grand slams.

"I don't believe that my happiness, my future happiness is gonna depend on if achieve one more grand slam than the others or if the others achieve more grand slams than me," Nadal said.

"I am super satisfied and feel a very lucky person in general for all the things that happen to me in this life.

"You can't be always frustrated if the neighbour has a bigger house than you or a better phone or a better thing.

"I'm not going to be frustrated if Novak or Roger finishes the career with more grand slams than me."

To make it through to the last-four, Nadal had to survive a tense five-set battle with Canadian rising star Denis Shapovalov.

Nadal was two sets up, before struggling with stomach issues in the scorching Melbourne heat, but managed to close out the match.

Crucially, Nadal will have an extra day off to prepare, with his semi-final not scheduled until Friday.

Australian Associated Press