Roger Federer said Sunday's US Open victory over Andre Agassi was the best of his six Grand Slam victories.
Federer won 6-3 2-6 7-6 (7-1) 6-1 to retain his title, and admitted: "This is the most special one for me, to play Andre in the final of the US Open.
"He's one of the only living legends in tennis we still have.
"To play him in this situation, with him towards the end of his career and me on the top of my game - I knew that this was going to be very special."
The victory was Federer's eighth in a row against the 35-year-old American, but the world number one said he still relished the battle.
"I'm amazed that I could hang with him throughout the last few years," said Federer.
"He got me a few times early in my career where I maybe looked like a little schoolboy.
"For me, that I could turn it around is fantastic and we can have an even battle.
"I look up to him because he's been around so long with great results. There's a lot of respect from my side."
And Federer remains at a loss to explain an ability to rise to the occasion that has seen him win an incredible 23 straight finals.
"I still can't believe how well I have been playing in the last couple of years," said Federer.
"I amazed myself that I can back it up one after another. I wonder why I always play so well, especially on the big occasions."