Melbourne: Austria's Dominic Thiem stunned Rafael Nadal in an "epic" four-setter Wednesday to send the world number one tumbling out of the Australian Open and set up a semi-final against Alexander Zverev. The fifth seed, beaten by Nadal in the last two French Open finals, battled past the Spaniard 7-6 (7/3), 7-6 (7/4), 4-6, 7-6 (8/6) to deny him a crack at a record-equalling 20th Grand Slam title. He will now meet German seventh seed Zverev, who shattered the dreams of veteran Stan Wawrinka 1-6, 6-3, 6-4, 6-2 to book his maiden place in a Grand Slam last four.

Awaiting the winner of that clash will be either seven-time champion Novak Djokovic or six-time winner Roger Federer, who meet in the other semi-final. "All the match was on a very good level, I think we are both in great form," said Thiem, only the second Austrian to make the Melbourne semis after Thomas Muster -- the man he sacked this week as an advisor. "Today I had the feeling I was lucky in the right situation... it is necessary because he is one of the greatest of all time. You need some luck to beat him." Thiem added that he was ecstatic at beating "a great champion" and "really proud how I stayed in the match", which he called "an epic".