When Federer beat Nadal at the 2007 year-end championships in Shanghai, the first chapter came to a close with the men on fairly even footing. Nadal had won eight of their 14 meetings, including three at Roland Garros, where the red-clay court best suited his extraordinary gift of grit. Federer had six victories, including his fourth and fifth consecutive titles at Wimbledon, a stylish venue befitting his versatile game.
It wasn't surprising that Nadal beat Federer in 2008 clay finals at Monte Carlo, Hamburg and Paris, but when he stunned the Swiss champion in a Wimbledon final for the ages, the dynamic shifted dramatically. In the second stage of their rivalry -- going into Thursday's semifinal at the Australian Open -- Nadal had won nine of 12 matches and the Grand Slam score stood at a resounding 4-0. That included the 2009 final in Melbourne that reduced Federer to tears.
For nearly five years, Federer hadn't beaten Nadal in a major, an eternity in tennis, especially when you are widely viewed as the greatest player of all time.
"I'd like to get a chance to play him again here," Federer said before Nadal beat Tomas Berdych in the quarterfinals.
He seemed to mean it. Federer arrived in high spirits, with a 24-match winning streak and a more aggressive game plan against Nadal from coach Paul Annacone. You got the idea that, if Federer was going to break the cycle, this was going to be the time. For most of three sets, it worked.
But in the crucible of that third set -- a mini-series in and of itself -- Nadal was mentally tougher, as he always seems to be. After Federer saved four set points in the tiebreaker, Nadal converted the fifth with this familiar sequence: wide serve, a run-around forehand and an on-the-run Federer forehand into the net.
And so, Nadal again beat Federer, 6-7 (5), 6-2, 7-6 (5), 6-4 at Rod Laver Arena to advance to his second Australian Open final. He will meet the winner of Friday's Novak Djokovic-Andy Murray clash Sunday.
Nadal -- perhaps because he was winless against Djokovic last year -- seems to be rooting for Murray.
"Andy has to play more aggressive than usual," Nadal said in his on-court interview, then paused. "That's my advice. My advice is probably not very good because I lost to Novak six times."
Watching Federer-Nadal is like reading the J.R.R. Tolkien trilogy for the third time. It is familiar and comforting, yet there still are moments that take your breath away. This was the 10th meeting in a major for the two, equaling John McEnroe and Ivan Lendl for the most ever.
"For me, is an honor to play against Roger," Nadal said afterward, calling Federer the greatest player in history, along with Rod Laver. "I always saw him in front of me, one player better than me."
Note the use of the past tense. Nadal now holds a commanding 18-9 head-to-head lead, doubling up Federer. Moreover, Rafa has won eight of his 10 Grand Slam matches against Federer, who is 30 years old. After this one, it is difficult to imagine the aging process reversing itself.
The deal-breaker in this classic matchup always has been Nadal's looping forehand, hit high to Federer's backhand. It has forced Federer to retreat and opened up space for Nadal. This time out, perhaps enlightened by Djokovic's dominance of Nadal a year ago, Federer seemed to be making a concentrated effort to exploit Nadal's backhand -- just as Rafa has historically worked on his. Federer tried to hang along the baseline until an opening presented itself, then struck quickly.
Serving at 4-3 in the first-set tiebreaker, Federer pounced, sprinting into net when Nadal floated a slice and drilling a forehand volley -- that clipped the baseline -- for a winner. On the next point, he came in again and hit a sweet, short backhand half-volley Nadal couldn't retrieve. On his third set point, Federer converted when Nadal's backhand went long.
The second set was yet another demonstration of why Rafa is, well, Rafa. Federer, serving at 2-3, pitched a nearly perfect game, but Nadal was better. Federer was in a commanding position at net, having just knocked off a backhand smash, but a streaking Nadal took the ball 10 feet wide of the doubles alley and sent a running forehand past a flat-footed Federer. Rafa celebrated with a vintage, spinning, scissor-kick, fist-pump combination, and you could feel the momentum shifting. Nadal converted his third break point chance with another freakish passing shot, this one on the backhand side, and went on to win the set easily.
The third set had everything, including some terrific Australia Day fireworks, which stopped the action for 15 minutes. The intermission affected fussy Federer, who lost 11 straight points when they returned to the court. Federer was down love-40 serving at 0-1, yet rallied to hold. When Federer broke in the seventh game, Rafa broke right back in the eighth. Federer saved a break point at 5-6 to force the tiebreaker.
Leading 2-1, Nadal played it safe and watched Federer implode with two backhand errors, then spanked a forehand mishit for a backhand winner. Another Federer miss, a forehand into the net, left Rafa with a commanding 6-1 lead. Federer rallied with four straight points but couldn't make the running forehand that would have drawn him even.
Federer had chances in the fourth set, but they evaporated when the pressure was on. With Nadal serving at 5-4, he had two but couldn't convert. The difference in the match: Federer, feeling a sense of urgency, had 63 unforced errors, 29 more than Nadal.
This will be an especially tough loss for Federer to digest. He is the consummate professional and put himself in the best possible position to beat Nadal. Earlier in the fortnight, Annacone explained how in an exclusive email.
"He does a great job planning his schedule, training, competing, professional obligations and rest and recovery," Annacone wrote. "He has figured how best to manage his time and his schedule so this allows him to be prepared to play throughout the season.
"He loves tennis and has a great energy and desire to continue to improve and to continue to compete at the highest level."
Federer has failed to win the past eight Grand Slam events he has played. Whether that "highest level" will allow him to win a 17th major is an increasingly valid question.
Greg Garber is a senior writer for ESPN.com.