Melbourne, Jan 28 (IANS): Six-time Australian Open champion Roger Federer on Tuesday saved seven match points to register what would go down in history as one of his most challenging and emphatic victory in his illustrious career.

Delivering probably the greatest Houdini act of his career, Federer went past rising American star Tennys Sandgren in a five-set thrilling quarter-final clash and booked his berth in the last four of the ongoing Australian Open.

No.3 seed Federer won 6-3, 2-6, 2-6, 7-6(8), 6-3 in a match that lasted for three and a half hours at the Rod Laver Arena.

"You've got to get lucky sometimes," Federer said in his on-court interview. "I was just hoping that maybe he wasn't going to smash a winner, if he misses one or two (match points), who knows what's going to happen? I think I got incredibly lucky today.

"As the match went on, I started to feel better and just tried to play. I believe in miracles. There could be rain...Just let him finish me off in style, and he didn't do that. I'm still standing here and obviously just very happy," he added.

Next up for the Swiss legend is second-seeded Serbian Novak Djokovic or No. 32 seed Milos Raonic of Canada. Federer trails Djokovic 23-26 in their rivalry and has lost their past three matches in Melbourne, all of which took place in the semi-finals (2008, 2011, 2016).

However, he leads Raonic 11-3 in their series and won their lone clash at this event in 2013.