Roger Federer pulled off an heroic last stand, saving seven match points and turning the tables on Tennys Sandren for a 6-3, 2-6, 2-6, 7-6(8), 6-3  trip to the Australian Open semi-finals on Tuesday.

The third seed was tested for half the match by the burly 100th-ranked journeyman, looking something like a junior version of Rafael Nadal with a no-name sleeveless shirt.

Roger Federer battled through his quarter final match to beat Tennys Sandgren.  Photo Anne Parker International Sports Fotos Ltd/Alamy Live News

Federer, who was treated for what he called a tightness in his groin and leg,  survived after three and a half hours as he thwarted the upset hopes of the player who sneaked into a 2018 quarter-final here.

Federer confessed he could not believe his luck and at some low points thought he might be on his way back home after making a second great escape following a five-set win in the third round over John Millman.

“With these lucky escape, you have to play without expectations,” the 20-time Grand Slam champion said.

Tennys Sandgren nearly pulled off a giantkilling act.   Photo Anne Parker International Sports Fotos Ltd/Alamy Live News

“You know you should be off skiing in Switzerland. I’m lucky to be here so I might well make the most of it.

Federer won the opening set but dropped the next two before taking a medical timeout off court and then saving his lucky seven match points in the fourth set to stay alive

“I believe in miracles,” he said. “I’m incredibly lucky that he didn’t finish me off today,” adding: “I’ve got time to get ready for the semi-finals.

“You do feel a lot better in a few days.”

The Swiss could not really explain how he pulled out the win.

“You gotta get lucky sometimes, saving seven match points, you’re not in control

“He played his match and I got incredibly lucky. I felt better as the match went on, all the pressure went away and I just started to play.


.”I don’t deserve this one but I’m standing here and I’m obviously very very happy.”

Federer will take on the winner from Novak Djokovic and Canadian Milos Raonic in a semi-final, his 15th at the tournament.

The well-behaved Swiss draw a warning for an audible obscenity early on, a rarity for him.

After trailing an early break in the third and going off court for treatment, the momentum began to slowly shift.

Roger Federer said he got lucky in his win over Tennys Sandgen. Photo Anne Parker International Sports Fotos Ltd/Alamy Live News

Federer came back out to get on the board, holding for 1-3 but eventually lost the set to trail two sets to one.
But the inexperience Sandgren was unable to continue his giant-killing act, with Federer slowly turning the screws to the delight of another sold-out Rod Laver arena crowd.

Federer will be playing his 46th Grand Slam semi-final as he aims for an eighth Melbourne final

Federer can now claim the Open as his best major in terms of matches won after taking his 102nd win at the tournament.

Novak Djokovic set up a semi-final date with Federer with a quick-fire 6-3, 6–4, 7-6(1) defeat of Milos Raonic.
Novak Djokovic celebrates his quarter final win.  Photo Anne Parker International Sports Fotos Ltd/Alamy Live News
The Serb second seed never faced a break point and survived 18 aces off the Canadian’s racquet in a win lasting just shy of three hours.
Djokovic polished off a third-set tiebreaker on the first of five match points to move to his 50th meeting with Federer.
“I felt great on court, very focused,” seven-time tournament winner Djokovic said.
“The first two sets went exactly as I wanted, I got out of trouble in the third with a perfect tiebreaker.
“I felt comfortable serving, I knew the key element would be how many balls I could get back into play.”
Canada’s Milos Raonic was no match for Novak Djokovic.  Photo Anne Parker International Sports Fotos Ltd/Alamy Live News
Djokovic will clash with Federer in his 37th Grand Slam semi-final on what he called “my favourite tournament and favourite court in the world.”
Djokovic holds a 26-23 edge in his series with the Swiss icon.
“I have tremendous respect for Roger, playing him and Rafa have made me the player that I am today.
“I hope I can get through to at least one match point – let the better player win.”