Nine years ago, Andre Agassi and Pete Sampras met in the final at the U.S. Open. Sampras was 31 and, though no one knew it, playing his last tournament. Coming in, Sampras had scuffled to beat lesser players.
"He was playing not so great," said Agassi, sitting in the Roland Garros tennis museum. "But when he saw me on the other side of the net, nothing else mattered. It didn't matter, because he was comfortable in our many matches. He knew what he could do. Knew what he would do.
"It's the same for Nadal. He hasn't been playing that well, his confidence was low the first week of the tournament. But when he sees Roger out there, he'll feel relaxed, comfortable. They've played 24 times and Rafa has won most of them."
Hard to imagine the sight of the imperious Swiss, believed by many to be the best player of all time, as comforting. But Nadal has always had an exceptionally keen vision of his game, as well as his place in it.
Ultimately, Nadal wore down Federer 7-5, 7-6 (3), 5-7, 6-1. It was not a great match, running 3 hours, 48 minutes, but it was solid and satisfying.
And then he thanked life itself for giving him the opportunity to make this sterling piece of history.
"A big personal satisfaction, especially when you started [the tournament] without playing your best," Nadal said. "Finally, I was able to play my best when I needed my best.
"[The French Open] always is the tournament where I feel that I have more chances to win. This is my biggest chance of the year [to win a Grand Slam]. I know if I win this tournament, my season is fantastic. I then can play with more confidence and less pressure."
Thus, Nadal retains his No. 1 ranking for a few more weeks anyway, before Novak Djokovic threatens it again. Federer, who turns 30 in August, has never beaten Nadal here in five tries, four of them in the finals.
Coming into the tournament, Nadal had lost four straight finals to Djokovic. For that reason, he admitted, he came into Roland Garros with less confidence than ever.
In the eight Grand Slam singles finals between the Swiss and the Spaniard, Nadal has now won six.
How can Federer be the greatest of all time, his skeptics wonder, if he isn't the best player of his generation? Here's a thought: What if Nadal is the best player of his generation and, at the age of 25, building a résumé that one day will be considered the greatest ever?
The numbers suggest it is now possible. Nadal:
• Won his 10th major title, leaving him only six behind Federer's all-time-leading total.
• Earned his sixth championship at Roland Garros in seven years, tying him with Bjorn Borg (1974-75 and 1978 to 1981). The stylish Swede won his six titles in a span of eight years.
• Is the second-youngest man in history to win his 10th Grand Slam singles title. At 25 years, 2 days, Rafa is nearly a year behind Borg -- but he retired from the sport a year later at the age of 25. Rafa looks like he's good for another three or four more years.
Perhaps more interestingly, in the ongoing arms race for supremacy, Rafa beat Federer to No. 10 by 171 days. That means he can open up some more ground at Wimbledon and the U.S. Open, tournaments he won a year ago.
Another thought: If Federer, instead of losing six of eight major finals, had managed to break even, he'd be up 18-8 in the overall standings. That's a big swing.
After he ended Djokovic's 2010-11 winning streak of 43 matches in the semifinals, Federer sounded almost satisfied just to reach the final match.
"Almost feels somewhat like I've won the tournament, which is not the case," he said. "Silverware is still out there to be won."
In the grand scheme of things, Rafa has proved to be more adaptable than Federer. Although Nadal has been almost unbeatable on clay -- winning 11-of-13 -- he has evolved dramatically on Federer's favorite surface, the grass at the All England Club where he has won six titles. After losing the finals to Federer in 2006 and 2007, Nadal changed the karma in a spectacular 2008 final there. Likewise, Rafa won his first Australian Open championship in 2009 and his first at the U.S. Open a year ago.
There were times, usually critical junctures, when it looked like Federer just didn't have the requisite energy for the task. He would hum along for a few games, a frail forehand would find the net and Nadal would move back ahead.
Nadal beats Federer -- 17 times now out of 25 -- because he is both fearless and relentless. Here is an example from the first set, with Federer serving at 5-all:
In a position of supreme advantage, Federer fired a shot indelicately at what we will call Nadal's midsection. Somehow, the Spaniard got his racket on it, and Federer's scrambling response was a floater just above the net, which Nadal crushed with a swinging forehand.
It might have been the pivotal point of the match, because it gave Nadal the break point he needed to take that first set. Federer tapped out, hitting an awkward forehand into the net.
Nadal, who had saved a break point and trailed 2-5, won the last five games of the frame. The aggressive Federer, who had come out serving as well as he did against Djokovic in the semifinals, was gone. He returned, just as the rain was gathering over Court Philippe Chatrier. Following a 10-minute rain delay, he broke Nadal in the 10th game of the second set, saving two set points in the process.
Federer, whose backhand had been deteriorating through the match, lost control of his forehand in the tiebreaker, falling into a 0-4 hole. Rafa ran around another backhand and pounded a forehand winner for his second set.
Taking advantage of Nadal's dropping level, Federer won the third set but the effort cost him dearly. There wasn't much left as Rafa, rejuvenated, ran out the clock on the proud champion.
"I thought Rafa played well," a red-faced Federer acknowledged later. "He dug deep to come back in the first set. It was tough all the way through.
"For me, of course it's a bit disappointing, but it was a good tournament for me, as well. Ten Grand Slams is a lot. He knows this; I know this; everybody knows this. It's really good for him."
Nadal, because of his great defensive skills, did not have to take the kind of risks Federer did. He finished with 39 winners and only 27 unforced errors, plus-12, while Federer's numbers were 56 unforced errors and 53 winners.
For Federer, though, this tournament reinforced his ability and desire to hang with the big two.
After beating Djokovic in the semifinals, Federer wagged his index finger, an admonishment to the critics, perhaps, who wondered if he still had any big-time matches left in him. In his postmatch news conference, Federer expounded on this angle.
"I mean, I told people that we should wait six months after the Australian Open when people thought Rafa and me were done," Federer said. "It's unfortunate that it goes so quickly at times. Now we're back in the finals and now it's different talk again. I don't go even there, because I knew it wasn't the case.
"He's happy to be Rafa, I'm happy to be Roger. That's why we like to play each other, maybe."
But Federer may think otherwise if Nadal continues to close the Grand Slam gap at this rate.
Greg Garber is a senior writer for ESPN.com.