World number three, Roger Federer has admitted he was lucky to have driven past unseeded American Tennys Sandgren in a sensational Australian Open quarter-final match.
Federer, who is reaching his 15th semifinal in the past 17 years, won 6-3 2-6 2-6 7-6 (10-8) 6-3 over the world number 100 in three hours and 28 minutes.
“I didn’t deserve this one but I’m standing here and I’m obviously very happy” said Federer, who had a medical timeout in the third set for a groin problem before saving seven match points in the 4th set to complete a comeback.
“You’ve got to get lucky sometimes I tell you that. Sometimes you’re not under control.
“I just hoped he wouldn’t smash a winner, just keep the ball in play and if he does miss one of two then see what is going through his mind.
“As the match went on I felt better and the pressure went away.”
The 20-time Grand Slam champion will play Serbia’s defending champion Novak Djokovic or Canadian 32nd seed Milos Raonic in the last four.