But as so often has been the case in their 10-year series, Friday night's Australian Open semifinal was much more about Nadal's brilliance than Federer's failure.
Reducing Federer's perceived strengths -- in this case a more aggressive net game he had embraced and sharpened this tournament under the influence of new coach Stefan Edberg -- to just another opportunity for a blistering passing shot, Nadal all but cruised to a 7-6 (4), 6-3, 6-3 victory.
Nadal will meet Federer's Swiss countryman Stanislas Wawrinka in Sunday's final, moving ahead of Pete Sampras and equaling Ivan Lendl's 19 Grand Slam finals appearances.
A victory for Nadal Sunday will tie him with Sampras at 14 Grand Slam titles and make him the first man in the Open era -- and only third in history -- to win each of the four major titles twice.
But Friday night was more about one of the great non-rivalries, as Nadal is now 23-10 versus Federer overall, 9-2 in Grand Slams and 9-6 on hard courts.
After a tight opening set in which Federer fought off two break points in the seventh game and one more in the ninth, Nadal took control in the tiebreaker with a 5-1 lead built mostly on Federer errors, and played the rest of the match on his terms.
That translated to a dizzying array of classic Nadal groundstrokes -- on the run and standing still, cross court and down the line, from low forehands that appeared unhittable to crackling backhands that froze Federer at the net -- which made it stunningly apparent that this was not going to be Federer's night.
In contrast to his quarterfinal and semifinal victories against Jo-Wilfried Tsonga and Andy Murray, Federer lost control Friday by virtue of Nadal's harder and deeper serve returns, which forced him into more errors. And mentally, Federer looked frustrated from late in the second set on, seemingly not playing with the same conviction as he had throughout the tournament.
Through the seventh game of the second set, Nadal had yet to face a break point and had lost only three points total on his serve, including one double fault.
"He did a good job," Federer said. "He didn't make many errors, even though I was trying to hit hard and flat. I tried to play my game. Sometimes I did play very well and sometimes I didn't. But he overall was more consistent. He deserved to win tonight. I mean, he was better."
A blister that had been rubbed raw on Nadal's left (racket) hand had to be rewrapped during a medical timeout early in the second set, and whether it was that delay or just the hopelessness of the match in general, Federer seemed to become increasingly agitated, complaining two games later (after Nadal held at 2-1) to the chair umpire about Nadal's trademark grunting.
"Nobody ever says anything," Federer was heard saying and then addressed it after the match.
"[It's not distracting] when he does it every point," Federer said. "But it goes in phases. One point he does and [one point] he doesn't. That's just what I was complaining about. It had no impact on the outcome of the match … "
Nadal seemed taken aback by the charge.
"When I am playing, when I am hitting the ball during the point, the last thing that I am thinking is try to bother the opponent," he said. "The only thing I am focusing [on] is try to hit my ball well. That's it.
"I am sorry if I bothered somebody, but I never did in the past. … Nobody in my career told me nothing about this, that I am bothering the opponent. … I think I did the normal things that I do in every match."
That was obviously the problem for Federer, though Nadal called it his best match of the tournament.
"I think he tried to play very aggressive, taking the ball very early," Nadal said. "But if you go to YouTube and you see the video of 2012 match [in which Nadal defeated Federer in the semis here in four sets], you will see that he was playing very, very aggressive, too. …
"I saw that video today. I see the way that he will try to play again. But the important thing for me is to serve well, to resist [his charge] in the beginning [because] when the match is longer, that's more difficult physically to play with that intensity -- to play that aggressive [for] a few hours. Mentally and physically, it's very tough."
Classic Nadal, he once again became stronger, more precise as the match wore on, which he said was accomplished because he felt "more confident" with "more power in his legs."
After an uneven history here and missing last year's tournament because of a knee injury, Nadal, 27, said it was "emotional" being able to come back and reach his third final here.
"In 2006, I didn't have the chance to play [because of] the injury to my feet at the end of 2005 in Madrid," Nadal recalled. "In 2010 against Andy [Murray], I had to retire because of a problem in the knee; 2011, I didn't want to retire, but I had a strain on the muscle in my leg the third game of the match. Last year, I didn't have a chance to play here.
"A lot of years I didn't have a chance to play in this tournament that I really love so much with the perfect condition, so is very special I have the chance to be in the final here again."
As for Federer, 32, who has beaten Nadal in only two Grand Slam tournaments, both on the grass courts of Wimbledon, this tournament was still a success, he said, after a year in which he struggled with back problems and failed to reach a Slam final for the first time since 2002.
"I needed a good moment again because I've been going through a tougher time for some time," he said. "Even though you can say that Basel was better, Paris was better, London was better, the results were slightly better, but the game itself was not necessarily amazing.
"It was solid but what I like to do is take it to the guy. I like to be in command. That's what I was able to do now the last couple of weeks. So that's very encouraging. … This is a step in the right direction, and that's the way I want to go. I have a belief this could be a very good year for me again."