"I lost against the world No1 at the moment. That's the kind of guy you probably can lose against," Federer said.
"But I'm not going to accept it and say it's normal. It's not. I've beaten him a few times. I'm one of the few guys that's gotten a chance.
"Same with Stan [Wawrinka at the French Open] and a few guys that have given Novak a run for the money.
"Clearly I was always going to believe hard today that I was going to come through as the winner, but still always being humble knowing how tough it was going to be."
In the twilight of his career, Federer hasn't claimed a grand slam title since winning Wimbledon in 2012.
"I'm still very hungry and motivated to keep playing and a match like this is very helpful," he said.
"Of course I would like to have won but Novak played really well."
Grand Slam leaders
17:
Roger Federer (SUI)
14:
Rafael Nadal (ESP), Pete Sampras (USA)
12:
Roy Emerson (AUS)
11:
Bjorn Borg (SWE), Rod Laver (AUS)
10:
Bill Tilden (USA)
9:
Novak Djokovic (SRB)
8:
Andre Agassi (USA), Jimmy Connors (USA), Ivan Lendl (USA), Ken Rosewall (AUS), Fred Perry (GBR)
- AAP