A fighting Federer bowed out to Novak Djokovic in a straight-sets semi-final defeat 7-6 (7-1) 6-4 6-3 after forcing himself out on Rod Laver Arena.
The 20-time Grand Slam victor, however, got out of the blocks briskly on a hot evening to wrest early initiative as Djokovic struggled with his service games.
Novak Djokovic gives credit to Roger Federer for playing clearly not being 100% for their semifinal.
He thinks he's capable of adding two more major titles to his record-breaking trophy cabinet and is determined to returning to Melbourne Park next year.
The Serbian was in top form and won the match by 7-6 6-4 6-3 in the end after a frantic clash for the first set.
One key this time could be how Federer feels after dealing with a painful groin muscle while saving seven match points during a five-set quarterfinal win.
The second men's semi-final takes centre stage on Friday evening, with Zverev facing fifth seed Dominic Thiem for the right to take on Djokovic.
"The timeout today was just one of the things that need to be done to prevent any further problems, and once I was back in the match I felt I was probably going to able to finish which was a good thing. I want to say respect to Roger for coming out tonight, he wasn't at his best or even close to his best in terms of movement". "Nice entrance, nice send-off, and in between is one to forget because you know you have a three percent chance to win". "Didn't know that. Next time I got to check the linespeople".
The 38-year-old revealed in his post-match press conference that he swore in a mixture of languages, admitting that he was frustrated by the way he received the penalty.
"You never know what the future holds, especially at my age you don't know".
Asked if he believed he could still win Grand Slam titles, he said: "Yes, I do believe that". I understand. Back in the day I feel like we could speak to lines-people.
Federer saved more break points to force a tie-break but by now Djokovic had stopped missing and was finding some fine offensive shots of his own.